U.S. Navy Builder 1st Class John Armstrong, selected as a chief petty officer assigned to Naval Mobile Construction Battalion 25, raises a ceremonial U.S. flag flown in remembrance of 9/11 at the New Kabul Compound in Kabul, Afghanistan, Sept. 11, 2014. Petty officers first class selected as chief petty officers held a memorial service in honor of the 13th anniversary of the 9/11 terrorist attacks. 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.