A U.S. military investigation into a deadly March airstrike has found that a secondary explosion caused the deaths of more than 100 civilians in Mosul, Iraq.
U.S. Central Command, which oversees American military operations in the Middle East, said Thursday the investigation determined that Islamic State fighters had placed “large amounts” of explosives in a building that housed civilians and then began attacking Iraqi forces from that building.
When the coalition targeted snipers on the roof, the explosives detonated, killing at least 101 civilians sheltering in the bottom floors and four civilians in a neighboring structure.
U.S. Central Command said Thursday “weapons and structural experts concluded, based on extensive modeling, (that) the structural damage to the building was in a different location” than where the airstrike hit and was “in excess” of what could have been caused by the single GBU-38 munition used in the March 17 strike.
Neither the U.S.-led coalition nor Iraqi forces who called in the strike knew that civilians were sheltered in the building, Central Command said.
"Our condolences go out to all those that were affected," said Maj. Gen. Joe Martin, Commanding General of the Combined Joint Forces Land Component Command in Iraq and Syria.
The U.S. military looked at more than 700 separate video feeds covering 10 days of airstrikes in Mosul to determine the credibility of the civilian casualty reports.
The Pentagon has called the death of civilians in Iraq's northern city of Mosul a terrible tragedy.
"There is no military force in the world that has proven more sensitive to civilian casualties,” U.S. Secretary of Defense Jim Mattis said shortly after the strike. “We go out of our way to always do everything humanly possible to reduce the loss of life or injury among innocent people. The same cannot be said for our adversaries.”
At the time of the strike, the Iraqi military cited evidence it said showed that Islamic State fighters placed explosives at the site.
"All of [the building's] walls were rigged with bombs, and there is no hole or signs that it was an airstrike target," the Iraqi military's Joint Command said.
U.S. officials have stressed to VOA that the U.S. military is fully capable of striking one building while leaving its surroundings unscathed.