U.S. Marines and Sailors gather on the forecastle aboard the amphibious transport dock ship USS San Diego (LPD 22) in the U.S. 7th Fleet area of responsibility Sept. 11, 2014, to honor the victims of the 9/11 terrorist attacks and those who have since served. 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.