U.S. Air Force chief master sgts. kick off the third annual POW-MIA Remembrance Vigil run at Langley Air Force Base, Va., Sept. 20, 2012. Langley Airmen carried the POW-MIA flag non-stop, in honor of American personnel listed as missing and unaccounted for. (U.S. Air Force photo by Airman 1st Class Kayla Newman/Released)