PHOTOS: Looking back at 9/11

1 of 11: In this Sept. 11, 2008 file photo, then-Presidential candidates Sen. John McCain, R-Ariz., left, and Sen. Barack Obama, D-Ill. toss flowers into the reflecting pool at ground zero in New York, to commemorate the seventh anniversary of the Sept. 11 terrorist attacks. (AP Photo/Timothy A. Clary)