U.S. Air Force Master Sgt. Randy Knightner, 633rd Security Forces Squadron standardization evaluations noncommissioned officer in charge, carries a defensor fortis flag in his rucksack during the Security Forces 9/11 Ruck March to Remember in Amherst, Va., Aug. 25, 2011. The march began at Lackland Air Force Base Texas, was broken into 15 legs and will end at Ground Zero in New York. (U.S. Air Force photo by Airman 1st Class Racheal Watson/Released)