At least 105 Iraqi civilians were killed in a U.S. air strike in the northern Iraqi city of Mosul in March, a U.S. military investigation has concluded.
The bomb dropped on March 17 targeted two IS snipers from the extremist group Islamic State (IS), the lead investigator, Air Force Brigadier General Matthew Isler, said on May 25.
However, the strike detonated explosives that militants had placed in the building, he said.
Isler said 101 civilians who had gathered in the lower floors of the building were killed when it collapsed, while another four died in a nearby building.
Thirty-six civilians remain unaccounted for.
The United States had previously acknowledged it "probably" had a role in the deaths but said this was unintentional.
In October, Iraqi government forces launched a major offensive backed by U.S.-led coalition air strikes to recapture Mosul, the main IS stronghold in the country.