Vice President Dick Cheney (left) and Secretary of Defense Donald H. Rumsfeld arrive at the Pentagon Mall Entrance on Sept. 11, 2006, for ceremonies marking the 5th anniversary of the terrorist attack on the Pentagon. One hundred eighty-four people died at the Pentagon on Sept. 11, 2001, when a group of terrorists hijacked American Airlines Flt. 77 and crashed it into the western face of the building.