Airmen from Langley Air Force Base, Va., participate in the Security Forces 9/11 Ruck March to Remember in Amherst, Va., Aug. 25, 2011. Security Forces units from 15 bases across the country march to honor the 10th anniversary of the terrorist attacks on Sept. 11, 2001. (U.S. Air Force photo by Airman 1st Class Racheal Watson/Released)