**FILE** U.S. soldiers from the 2nd Brigade, 87th Infantry Regiment, 10th Mountain Division, secure the area after exiting a Chinook helicopter, Helmand Province, southern Afghanistan, on June 18, 2006. Insurgents shot down on Aug. 6, 2011, a U.S. military helicopter similar to this one shown during fighting in eastern Afghanistan, killing 30 Americans, most of them belonging to the same elite Navy SEALs unit that killed Osama bin Laden, as well as seven Afghan commandos, U.S. officials said. (Associated Press)