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NEWS | May 25, 2017

Department of Defense News Briefing on the Findings of an Investigation into a March 17 Coalition Air Strike in West Mosul

By CJTF-OIR Public Affairs

CAPTAIN JEFF DAVIS:  Hi, this is Captain Davis here at the Pentagon.  Just want to confirm you can hear us.

(UNKNOWN):  Loud and clear.

CAPT. DAVIS:  OK, great.  So get folks to gather round.  Hey, guys.  All right, so today we're joined by U.S. Army Major General Joseph Martin.  He is the commander of the Combined Joint Force Land Component Command for Operation Inherent Resolve as well as U.S. Air Force Brigadier General Matthew Isler.  He recently served as the CJFLCC-OIR air officer.

Generals Martin and Isler will brief us today on the findings of a command investigation into a coalition airstrike that took place March 17th in West Mosul.  General Martin, the CJFLCC commander who is in Baghdad will have a few words for us and then pass the mike to General Isler.  He joins us from Randolph Air Force Base and served as the investigating officer for this incident.

After that -- after that we will proceed to questions, we'll take some questions initially from here.  We do have a couple of callers on from out of town as well so we will offer them the opportunity for questions as well.  We will feed the audio from this briefing to the DOD pool line at 12:15.  And with that, we will get started.  General Martin, sir, we'll turn it over to you.

MAJOR GENERAL JOSEPH MARTIN:  Good evening, everybody.  This is Major General Joe Martin from Baghdad, Iraq.  I'm the commanding general of the Combined Joint Forces Land Component Command in Operation Inherent Resolve.  Today I'll address the coalition's investigation into the events of March 17, 2017 in the al-Jadidah district of Mosul, Iraq.  I would like to express my condolences to everyone affected by this incident.

Let me be clear that our objective is always to minimize the risk of collateral damage and any potential harm to noncombatants.  It is important to us that we take the time to look closely at this incident and see what lessons we can learn for the future.  We owe that to the victims and the families.  Following an alleged civilian casualty incident that occurred on 17 March in the al-Jadidah district of Mosul, Iraq, the coalition opened an Army Regulation 15-6 investigation.

The coalition was conduct -- the coalition conducted a total of 81 engagements in West Mosul on the 17th of March.  12 of those occurred in the vicinity of the al-Jadidah district.  Of those 81 engagements, one corresponded to an allegation of civilian casualties.  I subsequently appointed Brigadier General Matthew Isler as the investigating officer.

He assembled a team of 12 subject matter experts who invested over 1,600 combined hours of work assembling significant amounts -- amounts of evidence and they leveraged some of the Department of Defense's most specialized capabilities in producing the investigative report.  In the interest of providing an honest and transparent and reliable account, the team made every effort to be thorough and accurate.

I will now introduce Brigadier General Matthew Isler, the investigating officer for the incident.  He will cover the details and answer all of your questions.  Matt, over to you.

BRIGADIER GENERAL MATTHEW ISLER:  Thank you, General Martin.  Thank you, everyone, for sharing this time together today.  I'm going to provide you an overview of our investigation including the process, the events of 17 March, and my assessments.  I started after receiving authority by General Martin to conduct the investigation.  I assembled my team of subject matter experts in weapons, engineering, explosives, and law.

The team gathered evidence from multiple sources and conducted two inspections of the incident site.  We reached out to regional and Western news agencies and numerous nongovernmental organizations to gain information on the incident.  I'd like to express my personal thanks to the news agencies and NGOs who responded to our requests.  Included in the evidence are the testimony of eye witnesses including those of local residents, Iraqi civil defense personnel, and journalists on the scene.

We also reached out to numerous outside agencies including some of the best engineering, weapons, and explosives analysts in the Department of Defense.  These agencies completed comprehensive modeling and provided in-depth analysis to aid the investigation team.  In addition, we received great support from the government of Iraq and met with multiple ministries in the conduct of the investigation, including an Iraqi counter -- an Iraqi Counterterrorism Service, which I'll refer to as CTS, the Ministries of Interior and Defense, and the Combined Joint Operations Command Baghdad.

On the day and at the time of the engagement, Iraqi CTS forces were engaged in offensive maneuver to seize the al-Jadida district of western Mosul.  CTS soldiers had a continuous over watch of the district with visual observation of the structure.

Coalition intelligence surveillance and reconnaissance assets had previously confirmed ISIS control of the district and observed ISIS employed tactics, techniques and procedures, such as in placing defensive fighting positions in residences, seizing and employing vehicle-borne improvised explosive devices and improvised explosive devices, engaging CTS with direct and indirect fire.

Coalition intelligence, surveillance and reconnaissance assets observed ISIS fighters forcibly evict families from their homes in the district and local residents described evictions by ISIS during their interviews.  Multiple residents also described how ISIS fighters knocked holes in the walls of the buildings to move unobserved within the structures of the district, including the structure in question.

The structure was a two story reinforced cement building that was used at least in part as a residence.  The structure was well built and in some places, the walls were 30 inches thick.  The structure had an additional walled room on the roof and a partial basement in the rear of this structure.

CTS visual observers had been in direct observation of the area for over two days and had not observed civilians enter or use the structure.  Due to poor weather, coalition intelligence surveillance and reconnaissance of the area had been limited.

Neither coalition, nor CTS forces knew that civilians were sheltered within the structure.  According to witness testimony, ISIS fighters knew the presence of the large number of civilians within the structure and had interacted with those civilians.

While CTS was seizing the district, CTS visual observers within 100 meters of the structure identified two ISIS snipers, effectively engaging CTS soldiers from the defensive fighting position built into the second story of the structure.  Iraqi CTS commanders received reports of CTS casualties, approved the request for a coalition strike to neutralize the snipers and coordinated with an Iraqi forward air controller to prepare the strike request.

After a consultation with coalition advisors, the request was sent to the coalition strike cell, a joint fires and control center under the command of a target -- of a coalition target engagement authority.  The strike cell evaluated intelligence on enemy activities, historical civilian population reporting and the activities of friendly forces.

Weaponeering experts analyzed available weapons and recommended a weapon and a fusing option to achieve the required effect of neutralizing the ISIS snipers, while protecting friendly forces and minimizing collateral damage.  The target engagement authority positively identified the snipers, selected a GBU-38 Joint Direct Attack Munition with a delayed fuse and authorized the engagement.

The target engagement authority approved the engagement in accordance with the applicable rules of engagement, including specific provisions related to collective self defense and the law of armed conflict.  The engagement satisfied the criteria of distinction, proportionality and military necessity required by the law of armed conflict.

At 0824 on 17 March, 2017 in accordance with the applicable rules of engagement and the law of armed conflict, a coalition U.S. aircraft delivered a single GBU-38 precision guided munition against two ISIS snipers, engaging the Iraqi CTS.  Neither coalition nor CTS forces knew that civilians were sheltered in the bottom floors of the structure.

The GBU-38 detonated on the second floor of the front of the structure.  The detonation ignited a large amount of explosive material, which ISIS fighters had previously placed in the rear of the house.  The secondary explosion triggered a rapid failure of the structure, which killed the two ISIS snipers, 101 civilians sheltered in the bottom floors of this structure and four civilians in the neighboring structure to the west.

An additional 36 civilians who are believed to be connected to the structure remain unaccounted for.  Iraqi civil defense excavated the structure and found 101 casualties in the bottom floors of the structure.  This investigation analyzed this structure and post blast effects using three methods; post blast analysis by explosive ordinance disposal experts, which included chemical analysis of samples taken from the site, structural analysis and weaponeering analysis.

Each of these three analytical methods indicated a single mode of causation and effects.  First, post-blast analysis conducted by coalition explosive ordinance disposal teams detected explosive residues that are common to ISIS explosives, but are not consistent with the explosive contents of a GBU-38.

The senior U.S. explosive ordinance disposal officer concluded based on the chemical signatures of the explosives and the modalities of crater and observed damage to the structure that the residues were linked with multiple explosive components in place by ISIS.  Explosive ordinance disposal analysis also determined that the quantity of explosives would have been significantly greater in the explosive material contained in a single GBU-38.

Second, structural engineering analysis concluded that the overall structural damage and the crater at the rear of the building were not caused by the low explosive weight of a single GBU-38.  Instead, structural engineering analysis determined that the ISIS emplaced explosive material conservatively contained more than four times the net explosive weight of the GBU-38, which contains 192 pounds of explosive material.

This analysis is consistent with Iraqi findings, which determine that a coalition munition was not responsible for the structural failure of the building and the deaths of the civilians inside.  Third, comprehensive analysis by a weaponeering expert teams determined how and where the GBU-38 entered the structure; where the weapon detonated; and predicted weapons results.

The GBU-38 entered the roof at the -- near the front of the structure, and detonated while breaching the roof of the structure.  Observed damage throughout the site confirmed the locations -- the location of the weapon's impact, the results on the roof, and at the front of the structure.

To summarize, these three methods of analysis, including post-blast analysis with chemical testing, structural analysis, and weaponeering analysis all confirmed that the GBU-38 entered the roof at the front of the structure, detonated while breached in the roof, and would have resulted in localized damage to the front and second-floor areas of the structure.

The overall structure would have remained intact and not collapsed.  The GBU-38 detonated a large amount of explosives emplaced by ISIS.  Conservatively, more than four times the net-explosive weight of the GBU-38, which resulted in the collapse of the structure, the death of 101 civilians within the structure, and the death of four civilians in the neighboring structure to the west.

In conclusion, I will emphasize several key points.  The coalition takes responsibility for the airstrike conducted on 17 March.  The coalition conducted an open, transparent investigation to establish full accountability.  One recommendation of the investigation currently being pursued by Combined Joint Task Force-Operation Inherent Resolve is to create a full-time, dedicated civilian casualty assessment team to work with Iraqi civil defense to help assess allegations of civilian casualties.

This team's creation will help speed the assessment process and provide increased accountability for strikes that may result in civilian casualties. 

The coalition has already adapted techniques -- tactics, techniques and procedures involving intelligence, surveillance and reconnaissance to aid in the identification of civilians held by ISIS as human shields or trapped while ISIS fights from their homes.  However, this engagement was conducted using all available intelligence, entirely according to stringent coalition rules of engagement and in accordance with the law of armed conflict.

The coalition employed a weapon that achieved the necessary military effect and would have limited collateral effects had ISIS not emplaced a large amount of explosive material within the structure.  This investigation determined that ISIS deliberately staged explosives and snipers to harm civilians.  ISIS knew of the large number of civilians sheltered in the structure; had interacted with the civilians. 

ISIS emplaced a large amount of explosive material in the rear of the residence for the purpose of killing civilians.  ISIS emplaced a sniper position in the rear of the building next to the explosives and attacked CTS to draw fire onto a structure they knew contained a large number of civilians.

The coalition remains committed to taking all feasible measures to protect civilians as we support our Iraqi partners in the liberation of Mosul and the defeat of ISIS. 

I'm grateful for our time today, and remain available to take your questions.

CAPT. DAVIS:  All right.  Thanks.

Operator, over to you.  I know we had some people that are dialed in.  We'll give you an opportunity to give them a chance to queue up and then take questions here.

OPERATOR:  Thank you.

If you would like to ask a question, please press star-one and you will be prompted to record your first and last name.  Please unmute your phone when recording your name.  To withdraw your question, press star-two.

CAPT. DAVIS:  We'll start with a few questions here.

Courtney Kube from NBC News.

Q:  Hi.  Thank you, General Isler; a couple of things.

So, the CTS, when you say that they had been watching the building for two days, is it fair to say that they had 24-hour surveillance on it for those two days?  And that because of the bad weather, there was no overhead ISR of the building?  Is that -- is that fair?

BRIG. GEN. ISLER:  Courtney, thank you.  I appreciate the question.

And I think it leads to the bigger question of positive identification.  And let me just talk through that, and those two aspects you brought up -- coalition ISR and direct observation in particular.

First, the coalition abides by the law of armed conflict and considers all persons and structures to be civilian in nature and protected from attack.  There are a number of methods that coalition forces use to positively identify combatants.  I'm not going to go into detail on those as they relate to coalition ROE, which is classified, but I'll address your particular question on visual observation and the use of full-motion video used to positively identify.

First, the visual observation piece.  In this case, CTS soldiers were in direct visual observation of two ISIS snipers who were conducting a hostile act of attacking CTS soldiers from a defensive fighting position in the structure.  On 14 March, CTS soldiers had seized the area, including the area within 100 meters south of the structure and established observation positions over the district, which -- including over the structure. 

From these positions, CTS visually observed the sector, including the structure in question.  They used their eyes and optical augmentation like scopes and binoculars.  And in this case, the observation position was within 100 meters directly to the south.

CTS could directly see the structure and the defensive fighting position.  However, as you noted, visual observation does not mean that they were omnipotent.  It doesn't mean that they could see all angles of the structure.  CTS could see the rear of the house where the snipers and the defensive fighting position were.  But they could not see parts of the north-facing front of the house.  So there were blind zones, and that's the nature of the urban environment.

Second, we'll discuss the full-motion video in this case used by the coalition.  Coalition intelligence, surveillance and reconnaissance have been observing and characterizing the area ahead of ISF maneuver since even before operations in west Mosul began on the 19th of February.

Coalition advisers helped the ISF plan its break-in and maneuver to factor in known areas occupied by civilians.  In this district, coalition ISR observed, and witness statements corroborate that ISIS had forcibly evicted families from their homes in the area and prepared defensive fighting positions.  At least one of the families in the structure was a family forcibly evicted by ISIS.

However, due to weather, coalition ISR was degraded on 15 March and 16 March.  And coalition ISR could not observe the district with full-motion video ahead of this engagement.

So when considering the strike the coalition target engagement authority took all these factors into consideration.  He considered the operational intelligence that CTS was proceeding into the district in a planned attack in an area that CTS had visually observed for over two full days.  And CTS had observed no civilian activity.

The target engagement authority considered the structure was in an area that coalition force ISR had observed ISIS evict families and prepare engagement areas.  The TEA also considered operational intelligence that CTS visual observers reported ISIS snipers engaged in a hostile act and that CTS leadership reported CTS soldiers taking casualties and requested assistance.

The TEA also considered the overall characterization of the area based on multiple sources of intelligence.  And the TEA determined the ISIS fighters were conducting a hostile act and used proportionate force to defend CTS.  I understand that answered the question.

Q:  Yeah, it does, it just - ask one more.  So because they - it was visual surveillance as opposed to some kind of an overhead ISR, is it your assessment or the investigation's assessment that the civilians in the building were being held hostage?  Or you just couldn't see a side of the building where they may have been coming and going during those two days?

BRIG. GEN. ISLER:  So, in this incident, and - and I'll be very narrow, it applies to this incident.  In this incident, I assessed that the civilians went there and remained there up until the day prior voluntarily.  The - the home was owned by a very well-known elder in the community, very well-regarded.  And he invited people to shelter within the home and that's from multiple witness testimony.

The home was well-known by neighbors as a very strong place to seek shelter.  They described it as extremely well-built with very thick walls.  And in this case, they sought shelter in the basement because it was the most safe and in the first floor because there was a restroom and a little bit of overflow in that area.  And the - we - I personally spoke with someone who'd been in the structure days prior.

And that person was evicted with his family from his home, went to a follow-on structure, and eventually came to this structure seeking shelter.  However, the night prior, so at 4:00 p.m. the night prior to the attack, ISIS fighters went to the next-door neighbor and told the next-door neighbor to leave the area.  That neighbor said "I built this home, I'm going to die in this home, I'm not leaving and I'm not taking my family out."

And ISIS said "well, that is on you.  What happens to you is on you and not the result of ISIS."  And ISIS fighters said "do not leave your house or we will consider you an enemy.  When you leave your house, we will kill you."  So he understood that night, so the night prior to the engagement, that he was not to leave his home.  And we don't know whether those in the structure that - the engagement, so in the structure in question were given the same warning.

It was likely that they were given the same warning but we don't know that.  But the original reason that they went there was they sought shelter and they were invited and so that was the purpose of their entry.  However, ISIS fighters did know that they were in the structure and interacted with those civilians.  I want to make sure that answers your follow-up question.

Q:  It does, thank you.

CAPT. DAVIS:  Next, we'll go to Michael Gordon from the New York Times.

Q:  I think you just answered my main question which is that you have no - no proof that these people were herded in there or forcibly held there.  But - but you still think ISIS put the explosives there to take advantage of the situation.  But just a quick follow-up question, at what level was the strike approved?  Was this done by a general officer?

Have you ever seen this sort of tactic employed anywhere else in Mosul, putting explosives in a building where civilians were known to be in the hope that the coalition would strike it?  And I just think if you could provide a little better explanation as to how you're going to avoid a repeat of this situation, I understand the extenuating circumstances but how do you stop this from happening again?

BRIG. GEN. ISLER:  Michael, I'm glad we've got as much time as we need.  You gave a lot of battle space there.  Thank you.  Let me first address with, it doesn't - to me looking at this, it doesn't matter how the civilians got there.  There were civilians in the structure and as of the night before, ISIS knew that they were there.  Whether they put them there or they existed prior, at that point there's over 100 civilians within that structure.

And - and I think that that's the germane point on this.  So let me go into that TTP in just a moment.  Your other question is, under what authorities did - was this engagement conducted?  And so there is - this engagement was approved by the target engagement authority.  Because of the numbers of target engagement authorities, I'm not going to be specific as to the rank.

However, there has been no change in - in coalition force ROE prior to this.  And so the coalition force ROE that was in effect last Fall remains the coalition force ROE that was used in this case.  The rules of engagement that the coalition's operating under is the same as they were previously.  As far as the tactics, techniques, and procedures, in this case, ISIS knew that there was a large number of civilians within the structure.

That is according to multiple witness testimonies.  ISIS also, by multiple witness testimony, interacted with civilians and ISIS had fighters staged out in front of the structure as just a matter of practice.  They had fighters that were staged out in front - in front of there.  ISIS emplaced explosives on top of those civilians in the second floor at the rear of the house.

We know that by modalities of the cratering and the chemical signatures of the cratering.  And at least 1,000 pounds of TNT equivalent which is more than four times the weight of explosives in a GBU-38.  Additionally, the distribution and location of that were significantly different than could be - have been created by a GBU-38.  They put accelerants in it, they set det cord, they enhanced the explosives with an accelerant to make it more sensitive for sympathetic detonation.

And then ISIS staged an attack within full view of CTS visual observers.  Now, ISIS could have conducted sniper attacks from anywhere.  This building was tall but it wasn't the tallest.  This building was an effective location, but it wasn't the most effective.  And so if you went in the area, it's probably not where, if you were the best sniper in the world, that you would have set up your position.

There were other areas that were more advantageous for an unobserved attack, and that were empty of inhabitants.  This was not a cache.  ISIS took explosive material and staged it on the second floor.  Within line of sight of CTS, you could put a cache anywhere.  You wouldn't put it within direct line of sight of your enemy forces.  And then they engaged CTS from the explosive location.  They put a lot of work into this set up. 

You asked about other TTPs.  We've seen this -- this exact TTP or similar TTPs on multiple occasions to include them locking civilians within structures.  And I'll go into that in just a moment.

On one particular occasion, 28 March, we saw the same TTPs -- it was 11 days after the 17 March incident.  We recorded with full-motion video.  We saw ISIS fighters forcibly move civilians through wormholes in the walls between structures.  They even used deadly force on civilians who resisted that moving.

ISIS fighters placed accelerants on the roof of that structure, including industrial-size propane bottles like one observed within the rubble of the structure in question on 17 March.  ISIS fighters then conducted attacks from the structure on ISF and attempted to draw coalition attacks.  Those civilians were not harmed by a follow-on coalition attack, and it illustrates how we've adjusted out TTPs. 

You asked about our TTPs, and so going forward we discussed -- hey, we -- ISIS has this TTP, and the coalition recognized this.  We know this ISIS TTP.  ISIS uses civilians.  They lock them.  They hold them.  They weld them even in structures.  We've seen them herd them into structures, and then conducts attacks from those structures.

And as a result, coalition and Iraqi forces anticipate this tactic.  We look for ISIS moving civilians and creating entrapment of civilians.  I won't go into any more detail on the tactics, techniques and procedures the coalition forces uses in order to protect their methods and effectiveness.  But the coalition takes every feasible measure to protect civilians from harm.

Michael, does that answer your question completely?

Q:  It answers it partly.

CAPT. DAVIS:  Next, we'll go to Tara Kopp from Stars and Stripes.

Q:  Hi.  Thanks for doing this.

In previous briefings, we've been told that, you know, once CTS asks for air support -- (inaudible) -- upcoming contact, it can be a matter of minutes before -- (inaudible) -- reinforces -- U.S. or coalition air resources respond. 

Can you give us a ballpark of the timeframe between CTS contacting for support and the actual airstrikes?

BRIG. GEN. ISLER:  Tara, I don't want to go into response times.  But look, I think General Martin's introductory remarks say a lot about coalition support on that day.  This was a day in which CTS was advancing into an ISIS-held area.  On that day, coalition supported with 81 engagements.  And the speed of that is a function of the intensity of ISIS resistance and the speed of the Iraqi maneuver.

In terms of the speed of response, we effectively meet our coalition partners need for timely fires response and make a great effort to make sure that we're being timely, as well as precise and fully in consideration of all the factors that need to go into that engagement.

Q:  Okay.  And also earlier this year, after reports of the -- (inaudible) -- had a briefing where -- (inaudible) -- that maybe ISIS -- (inaudible) -- and that there was -- (inaudible) -- video of ISIS -- (inaudible).  But given the weather and the lack of the video feeds, I guess there wasn't video of ISIS -- (inaudible) -- on this one?

BRIG. GEN. ISLER:  Ma'am, on that day -- on that day, and in this engagement. there is no coalition force video available.  We have -- the aircraft that were supporting this engagement, we have their weapons system video, which is in cockpit recordings of the weapons displays at the time.  And that allows us to validate the exact weapon, the coordinates, the method of employment.

But the -- if you would say -- a targeting pod video of that, it's just a display of weather.  And so it's not useful for the purposes that we're talking about. 

So, in this particular engagement, we don't have video of -- of that area.  However, regarding the -- the tactics, techniques and procedures used by ISIS regarding hurting civilians, we do have video that we've shared previously.  And I will ask the CJTF public affairs to follow up with you on giving you access to that previously released video.

CAPT. DAVIS:  Okay.  For the operator, we'll take one from the phone here.

OPERATOR:  I'm showing no phone questions at this time.

CAPT. DAVIS:  Okay.  Great.  We'll just continue on here.

David Martin of CBS News.

Q:  Were you able to determine when the explosives were moved into the building?  Or do you assume that they were moved in during the period when you didn't have overheads? 

And just -- (inaudible) -- point of fact, is a GBU-38 what we call a 250-pound bomb?

BRIG. GEN. ISLER:  So, Dave, thank you.  It was a GBU-38 joint direct attack munition, which is a 500-pound weapon.  It's a 500-pound class weapon.  The entire weapon, including its casing and guidance, weighs 500 pounds.  If you rip that all apart and emptied out the explosives in it, that total net explosive weight contained within the GBU-38 is 192 pounds of explosive. 

When you adjust and compare that with what would be required, that explosive is in military-grade explosives, so it's a little bit more concentrated, but not substantially more concentrated.  And if you compare an apples-to-apples comparison of how much net explosive weight would be required, much more than the 192 pounds of explosive would have been required to achieve the effects observed.

So let me just describe what that -- those effects are.  So if you go to that structure in the al-Jadida district, and you stand at the back wall of the basement, and you face south toward where the CTS was, and you're directly underneath where the ISIS sniper position was.  It was on the second floor. 

In front of you is a wall that's 30 inches of mortar and rocks.  And another wall of the neighboring structure which is 15 inches of concrete.  That wall you can then stand in where that wall was, in the middle it's completely pulverized, meaning its little bitty bits of rock and it's shoved into the neighboring structure.

If you go outside of arms width, that entire wall is moved back into the neighboring structure, not pulverized but broken apart and moved deep into that, so that 30 inches of concrete.  If you look to your left and your right where there were 30 inches of concrete walls and -- and we're standing in an area that's 10 meters, 30 feet wide, both of those walls are completely gone.

Each of those 30 inch walls are completely gone and if you would, liberated.  The reinforced concrete rebar that was held -- held the floor above it, that 30 inch of reinforced concrete rebar is liberated, as well.  And that's what brought down the structure.

If you try to take that GBU-38 and put it right there, it wouldn't even dent any of those -- if you put it right there in the center of it, it wouldn't even dent any of those surrounding walls.  They would be intact, they'd have a little bit of facial damage on it but that's the most you could get.

If you put four times the net explosive weight of that and centered it in the room where that's centered, you couldn't even generate the same thing, it wouldn't produce enough net explosive weight to produce that that far away from those -- those areas.  So you would also have to take that thousand pounds and ideally distribute it along each of those walls to result in that damage.

So it's not just the weight, it's not just the location, it's also the distribution of that.  So in each of those cases, the most conservative estimate of that would be -- it would be 1,000 pounds of explosive to do that but it would have to be optimally positioned to be able to do that.

So it was likely even more than that.  To go back to your question about the 250 pound munition, there are additional munitions that are 250 pounds that were not used in this engagement.  I hope that answers your question.

Q:  The other part of it was did you determine -- were you able to determine when the explosives were moved into the building?

BRIG. GEN. ISLER:  So we talked to people that had been in the building, the -- prior to the engagement.  In general, they were not allowed on the second floor, so the -- if you would, the guests were in the basement and on the first floor.  It was possible to get to the second floor, but the second floor was pretty much closed off from the rest of the house.

There was a separate entrance from the street directly at the staircase and into the second floor that -- so the ISIS fighters that were on the street level could go directly up and get in the second floor where the sniper position was and were based on the modalities of the crater ring we assess that the additional ISIS-emplaced explosive was.

We don't know when they moved that into the residence.  It could have been moved in there prior to the night prior.  But we know that the night prior that they had delivered specific threats to the neighbor to not come out of his residence under threat of death and had asked him to leave and issued a warning indicating that something was going to happen.

And I recognize that as an opportunity, but I think what was -- what -- what -- it wasn't as important as when it was there as the importance for -- for me to be able to show that there was additional explosive material there and that the chemical characteristics of those explosive materials were unique and identifiable and toward ISIS type explosive materials.  I want to make sure that answers your question.

Q:  (off mic) did you -- did you review video from (inaudible) the weather closed in?  Because moving 1,000 pounds or more with accelerants of explosives if you had -- if you had eyes on the business, it would seem to be something you could check.

GEN. ISLER:  So the 15th and 16th were the two days prior to the -- to the attack.  In neither of those days did coalition forces have effective full motion video observation of this area.  ISIS, just by being in that area and seeing the weather, ISIS probably has had a -- and we know they have a good sense of when coalition force ISR is effective.

And they would have had the opportunity to move a significant amount of explosive material.  To -- to use a similar event, on the 28th of March, when we observed ISIS fighters move families -- or move civilians into the structure in a similar tactic and emplace a sniper position on it. There they moved a large propane bottle.

Depending on how much propane was in it, it could've been a hundred or 200 pounds, it took a multi person lift.  That took them about five minutes to get that thing up there and to prepare that for its intended purpose.


Next, to Lolita Baldor from the Associated Press.

Q:  I just wanted to follow-up quickly on -- on David's question.  So none of the people that you interviewed general and no eyewitnesses said that they saw ISIS planting explosives in that building?  You have no other third party either suggestions or evidence other than explosives ended up there?  But no one you were able to get to saw it happen or said that was happening?

BRIG. GEN. ISLER:  So, Lita, we know that that explosive was there based on how the damage went into that structure and how that energy was distributed.  We recognize that that is -- is unique in nature and laterally displaced in a different nature than the coalition force munition.

Additionally, its chemical signature is different.  In particular, chemicals that are not associated with a GBU-38 that were chemically tested and -- and so -- so in fact, let me just back up a little bit and -- and talk about some of the -- the additional capabilities that came into this assessment.

Q:  So...

BRIG. GEN. ISLER:  So in the -- in the...

Q:  ...can I just -- can I just -- can I just talk to you for a second?  I'm not questioning whether the explosives were there, I'm just -- I'm just curious that no one you interviewed was able to say they saw anything (off-mic)...


Q:  ...but no one you interviewed either...


Q:  ...was able to say.

BRIG. GEN. ISLER:  Yes.  So, Lita, we -- we did ask that question and no one saw ISIS move explosives into that -- into that area.  And however, there were multiple opportunities for that to happen and so we did not rule that out.

Q:  Great, thanks so much.



Nancy Youssef from BuzzFeed.

Q:  In the initial hours and days after this strike, the U.S. military says that there did not believe there were any civilian casualties by the strike?  I'm curious how your report addressed why the U.S. was unable to see -- (inaudible) -- if there were 700 videos and what not.  You made reference to U.S. officials will be designated to deal with civilian casualties.  Can you talk a little bit about why even as witnesses are kind of coming forward and body bags are piling up and all this that the U.S. did not know until local reporting came in.  What -- what did your investigation show about that?

BRIG. GEN. ISLER:  You bet.  What -- I'll -- I'll -- I think you're getting at a more broad question on accountability for numbers.  And so let me -- let me drill into that a little bit.  So to get accountability of numbers, we got a lot of outside help.  We reached out to six media outlets and one freelance journalist, elected officials, NGOs, Iraqi government agencies, individual citizens.

We did over 20 interviews in key leader engagements.  We've followed up on every feasible lead.  We started by estimating a number of personnel that were in the structure.  So two days prior on the 15th of March, a guest of the house moved his family into another house.  At the...


Q:  ...that accountability, I'm just getting at how -- what does it say about the U.S.'s ability to make post strike assessment, when it wasn't aware of -- (inaudible) -- and did the report address that question?

BRIG. GEN. ISLER:  Good and I think I'll get to your question in just a moment.  I'll -- I'll -- let me talk about -- I'll get to it because its -- its germane on how we found out how many people were there, which involves when Mosul civil defense was able to get there and attempt excavate -- to excavate the people.

So when those people -- when that family left, we estimated there were 140 people in the house so in the first floor and in the basement that included women and children.  And there was a consensus of -- of NGOs and media that between 137 and 140 people were in this structure in the days preceding the attack.

The attack -- the engagement happened on the 17th of March, in between the 17th and the 25th of March, Mosul civil defense which is part of Iraqi civil defense conducted a full excavation of the structure.  Mosul civil defense conducted the initial excavation while under fire and they took casualties.

And so they left the scene on the 17th of March, they paused from the 17th of March to the 22nd of March because CTS at this point had only moved up to the street on which that structure was and it was not safe enough to excavate.

During that time, there were discussions -- there -- there -- there had been speculation that something had happened and that Mosul civil defense had been identified that there -- that there were people within the structure, but they had suspended their excavation on the 17th.  They went back to it on the 22nd and they completed their -- their excavation by the 25th and excavated 101 casualties from the structure.

They identified them by name, age and where the family was from and they used on person identification and also the identification made by relatives.  So that's at the structure in -- in question.  Does that answer kind of why -- there was -- there was a delay because it was too dangerous an area for Mosul civil defense to continue their excavation.

Q:  And then the other question I had was have condolence payments been made and if not, what process has been placed for them if at all?

BRIG. GEN. ISLER:  OK.  So no condolence payments have -- have been made and under -- under appropriate circumstances, commands may consider providing solatia payments.  These are expressions of sympathy to those injured for the families of the deceased.  The payments are not intended to serve as compensation for loss or injury, but out of respect for the privacy of the families, we do not discuss the details of individual cases.

DAVIS:  All right, last call, any others -- oh I'm sorry, Courtney had a follow-up.

Q:  Hi there, just based on I think it was David's question, based on the way that you were explaining the -- the way that the structure is filled, it sounds like you believe that it was rigged to blow, not that there was just a -- it was like maybe a storage place where there was a lot of explosives but that they -- that ISIS may have actually rigged the building in a way that it -- so it would collapse.  Is that your assessment?

BRIG. GEN. ISLER:  Ma'am, I -- I -- absolutely.  So I have stood in that rear wall and it wasn't -- I had seen a lot of munitions effectively used and what was witnessed there was not just that a large amount of explosive went off, but it -- that it was positioned in a way that would liberate the walls of the structure.

And -- and so it would've taken -- when we initially did an estimation on the amount of explosive material required, we made an assumption that it was centrally positioned.  But when we do the modeling on how much explosive it would take to do that, you rapidly realize it would take a lot.

And so in -- in this case, the easiest way to achieve the effect that was observed in that structure, which was the liberation of very thick walls and the collapse of the structure, would be to distribute that explosive in a way that provided for those effects that were observed in the structure.

And so we attempted to show that in modeling and that's exactly what the model showed, was that with that explosive material positioned in a certain way, you could achieve the -- the effects and then confirm that hypothesis.

Q:  And then just one more and I appreciate you taking so much time to explain all this.  When -- in the initial -- your initial opening statement, you said 101 civilians were since killed and 36 remain unaccounted for.  If you have any sense of those 36 -- is it just a belief that they were killed in the actual explosion as opposed to the building being -- as opposed to the building being -- as opposed to the building collapse and being buried in rubble?

BRIG. GEN. ISLER:  So, the exact number of civilians that were in there -- in general, there's a consensus that two days prior there were between 137 and 140 and there -- we -- we discussed in detail our assessments.  And so let me -- let me also add in that we discussed our lineup with those of a major NGO who's heavily invested in this type of work and those numbers aligned up well.

Those lined up exactly with that -- with that major NGO.  So what happened to the others?  Very -- my -- I don't know.  But my assessment is that in the day -- in the days prior to the attack, either they left as other families were leaving the area as that attack began -- on the day of the attack that they escaped from -- from that area.  Or following the attack, they escaped as survivors from the attack.

And so we were not able to close the gap but I'm very confident in the 101 number identified by Mosul civil defense.  I'm very confident in the number of four in the neighboring structure immediately to the west.  Those were -- those were recovered by the owner of the home, neighbors, and relatives.  And I am not aware of any additional -- any additional casualties associated with this event.

We followed up on every lead from every one of the interviews that we did and every lead we were given from a media and nongovernmental organizations.

CAPT. DAVIS:  All right.  And with that, you have one more real quick one from Thomas Watkins from Agence France-Presse.

Q:  I know you've been talking about this a long time and I was away for a little bit so if you've addressed this before, I apologize.  Could you just say what amount of damage should the GBU-38 have caused?

BRIG. GEN. ISLER:  Good, so -- OK.  So we modeled this a number of ways.  We first reached out to Army Corps of Engineers.  They have an engineering research and development center.  They modeled the structure and they did that based on witness testimony and the testing of materials that we actually brought back from the site on our two visits.  They modeled it as a multistory structure with masonry infill walls.

The ERDC, Engineering Research and Development Center produced a formal written report that represented the technical opinions of a panel of ERDC subject matter experts on penetrating weapons' effects and specifically whether a single GBU-38 with a delayed fuse would cause the complete collapse of the structure.  The ERDC determined that the damage to the structure was not consistent with a GBU-38, that the GBU-38 functioned properly at the top of the front of the structure and would have not resulted in a collapse of the structure.

However, there was at least one other detonation at the rear of the building as shown by the signature in the ‘rubblized’ material.  The ERDC conducted three types of weapon simulations including multiple probability-based Monte Carlo simulations with varying material properties.  All the weapons simulations result in a conclusion that the GBU-38 functioned at the top of the structure at the front.

They also concluded that the GBU-28 did not account for the significant crater and the ‘rubblized’ material at the rear of the structure.  Instead they determined that there was a second detonation at the rear of the building that caused the collapse of the structure.  Separately, we reached out to the Defense Threat Reduction Agency's target and weaponeering and assistance Cell.

These are folks that have some of the most capable analysts in the Department of Defense.  We also reached out to the Naval Surface Worker Collateral Damage Methodology Group.  These groups ran a series of simulations and assessments including probability based Monte Carlo simulations run over 1,000 times.  They predicted no more than 16 to 20 percent damage to the structure and the total expected damage would be restricted to the second floor.

They determined that the damage to the structure was due to a much higher-level explosion than a GBU-38 with 192 pounds of explosive.  So to summarize, all of the analysis indicated that the GBU-38 entered the roof of the front of the structure.  It detonated while breaching the roof and was not responsible for bringing down the structure or affecting the basement.

Instead, a significant secondary explosive event at the rear of the structure brought down the structure.  I hope that -- does that answer your question?

Q:  Yes, thank you.

CAPT. DAVIS:  OK, and with that, General, thank you for your time.  And ladies and gentlemen, thank you.  J.T., did you have anything else for us while you're here?  OK.  Signing off from OSD public affairs.  Thank you, everybody.

BRIG. GEN. ISLER:  Thank you very much.