105 civilians died in Mosul airstrike in March, U.S. finds

Pentagon: ISIS filled site with explosives, fired at allies

WASHINGTON — A U.S. airstrike in March killed more than 100 Iraqi civilians by inadvertently setting off a large amount of explosives that Islamic State fighters had placed in a building in Mosul, according to a military investigation made public Thursday.

The Pentagon investigation of the March 17 airstrike put the primary blame on the Islamic State, also known as ISIS, asserting that it placed the explosives in the building and then had two snipers fire at Iraqi forces from the area.

The investigation concluded that 105 civilians were killed: 101 in the building that was bombed and four in an adjacent structure. Thirty-six civilians who were believed to have been in the area have not been accounted for. The toll is one of the highest in the U.S.-led campaign against the Islamic State, though the investigation asserts that jihadis’ explosives were mainly at fault.

Neither the U.S.-led coalition nor Iraqi forces were aware that civilians and explosives were in the building, the investigation concluded.

According to the investigation, which was overseen by Air Force Brig. Gen. Matthew Isler, the episode began that March morning when two Islamic State snipers in the city’s Jidideh section began firing at troops from Iraq’s counterterrorism service, which was fighting its way into west Mosul.

Isler said in a news briefing that his assessment was that the Islamic State deliberately created a situation in which the United States would strike the building and set off the explosions.

The Iraqis did request an airstrike, and the U.S.-led coalition

responded by dropping a single GBU-38 munition, which carries about 200 pounds of explosives, about 8:30 a.m.

The goal was to produce a blast that would destroy only the top floor of the building, which was described as a well-built concrete structure, and kill the snipers. The bomb that was dropped, coalition officials said, was not strong enough to have taken down the building.

But the blast set off the explosive material that Islamic State fighters had placed in the structure, causing it to collapse. Analysis of the debris found residue of explosive materials that Islamic State fighters are known to use but that are not used in the GBU-38.

In addition, the investigation said the main damage to the structure was elsewhere in the building from where the GBU-38 was dropped.

According to accounts from neighbors, the civilians went to the building voluntarily because it was one of the best constructed in the area; they took refuge in the basement to get away from the fighting.

The U.S.-led coalition was not aware that civilians had gone there, perhaps because bad weather interfered with reconnaissance in the two days leading up to the strike, Isler said. Nor did Iraqi forces always have a clear view of the area around the building.

The general said it was possible that civilians in the building were held against their will after they took sanctuary, though there is no proof that this is the case. Residents of the adjacent building, which was also damaged, he said, were ordered not to leave the night before the attack.

The airstrike was approved by the command center in Irbil. Isler would not disclose the rank of the officer who approved the strike, but it is usually done by a one-star general.

Isler said the U.S.-led coalition had adjusted its tactics and procedures to prevent a repeat of the episode. But he would not detail them, saying the changes were being kept classified so that the Islamic State would not know them.

The U.S.-led command has previously said 396 civilians have been killed in the more than two-year campaign against the Islamic State in Iraq and Syria, though some independent estimates run much higher.