Vietnam War POW and retired Air Force Lt. Col. John Yuill looks straight ahead during the posting of colors during the National POW/MIA Day ceremony, Sept. 21, 2018, at Sheppard Air Force Base, Texas. The 24-hour vigil that started at the track near Lt. Gen. Leo Marquez Boulevard North concluded at the Sheppard Club, in which Airmen gathered to pay respect for those captured or missing in action, past and present. (U.S. Air Force photo by Christopher Carranza)