SEALs were on Afghan rescue mission when killed

The 22 Navy SEALs and 16 other troops killed Saturday in Afghanistan were trying to reinforce other troops pinned down in a mission targeting a key Taliban leader, the U.S.-led military coalition in Afghanistan said Monday.

The statement was the most detailed account yet of the deadly crash of an American helicopter in eastern Afghanistan, the largest single-day coalition loss of life since the war there began nearly a decade ago.

NATO said the Chinook helicopter "was reportedly fired on by an insurgent rocket-propelled grenade while transporting the U.S. service members and commandos to the scene of an on-going engagement between ISAF and insurgent forces." Notably, the statement does not confirm that the Taliban shot down the helicopter, which is the working hypothesis of the senior military personnel leading the ongoing probe into the incident.

The exact circumstances of Saturday's crash have been murky since the initial reports began circulating of a mission gone awry. In the new statement, the military said a second detachment of troops -- identified by other military sources as elite Army Rangers -- were searching for a high-ranking Taliban leader when they engaged a group of insurgents armed with machine guns and rocket-propelled grenades. During the resulting firefight, the Rangers requested reinforcements, and the SEALS "were in-bound to the scene when the CH-47 carrying them crashed, killing all on board," the military said.

The statement also offered a fuller breakdown of the dead, which it said included five members of an air crew and 25 personnel from the U.S. Special Operations Command. Eight Afghan troops also died in the crash.