Jan. 22, 2007 -- In a troubling development that may signify a new vulnerability for U.S. troops, the Black Hawk helicopter that crashed northeast of Baghdad Saturday appears to have been brought down by a shoulder-fired surface-to-air missile, a senior military official tells ABC News.
Russian-made surface-to-air missiles are plentiful in Iraq but have only rarely succeeded in taking down American aircraft. U.S. helicopters are equipped with countermeasures designed to protect them from such missiles.
Officials believe this is only the second or third helicopter downed by surface-to-air missile since the U.S. invasion of Iraq in March 2003.
The downing of the Black Hawk helicopter, which killed 12 American troops, is still under investigation. The source says investigators are trying to determine what type of shoulder-fired missile was used.
It was almost certainly Russian made, but investigators don't know yet whether it was an SA-7 or a more advanced SA-14 or SA-16.
An al-Qaeda Web site called Al Hezbah took credit for the attack, a claim the military says it cannot confirm.