Last month's US helicopter crash in Afghanistan was the result of a rocket propelled grenade that hit the aircraft's tail rotor, according to a US CENTCOM report released on Thursday, DPA reported.
The hit sent the chopper spiraling to the ground, where it landed in a dry creek bed and burst into flames, the report concluded.
The strike killed 31 US special forces soldiers and seven Afghans in one of the deadliest single incidents involving foreign troops since the war began a decade ago.
Thursday's report confirmed Taliban claims that the radical organization had perpetrated the August attack.
The crash came amid mounting concern that Afghanistan remains unstable despite plans to withdraw US and NATO forces by 2014, although US President Barack Obama's administration maintains that the United States is making headway in the war-torn country.
The report said the soldiers' injuries likely left them "immediately incapacitated" and that they probably died quickly, although autopsies are still in the final phases.
The downed chopper was not caught in an ambush. Rather, it was the result of the enemy being at a "heightened state of alert" due to more than three hours of US and NATO air operations in the area, the report said.
The report also concluded that all personnel involved in the crash had followed protocol.