Jon Hartsock performs "Amazing Grace" in Oak Harbor, Wash., Sept. 11, 2014, during an event to commemorate the 13th 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. (U.S. Navy photo by Mass Communication Specialist 2nd Class John Hetherington/Released)