U.S. Airmen with the 455th Air Expeditionary Wing recite their re-enlistment oath during a ceremony officiated by Brig. Gen. Mark D. Kelly, left, the wing commander, at Camp Cunningham at Bagram Airfield, Afghanistan, Sept. 11, 2014, as part of an event to mark the anniversary of 9/11. Terrorists hijacked four passenger aircraft Sept. 11, 2001. Two of the aircraft were deliberately crashed into the World Trade Center in New York; one was crashed into the Pentagon; the fourth crashed near Shanksville, Pa. Nearly 3,000 people died in the attacks.