Why were five U.S. soldiers killed by an American bomber in Afghanistan? - CBS News:
The Pentagon concluded the deaths were an "avoidable" accident -- known by the contradictory phrase "friendly fire." It was the deadliest such incident involving U.S. fatalities in 16 long years of ongoing war in Afghanistan. It wasn't gunfire that killed the U.S. soldiers. It was a pair of 500-pound bombs dropped right on top of them by a U.S. warplane.