Members of the U.S. Army Chorus perform.
Members of the U.S. Army Chorus perform during the five-year observance of the Sept. 11, 2001, terrorist attack on the Pentagon on Sept. 11, 2006. Vice President Dick Cheney, Secretary of Defense Donald H. Rumsfeld and Chairman of the Joint Chiefs of Staff Gen. Peter Pace, U.S. Marine Corps, addressed the family members of the victims.