Retired Lt. Col. John Yuill, a Vietnam prisoner of war, spoke to Airmen about his POW experience during the opening ceremony for the POW/MIA Day vigil run at Sheppard Air Force Base, Texas, Sept. 14, 2017. Airmen carried the POW flag for 24 hours in honor and remembrance of all POW and MIA troops. (U.S. Air Force photo by Staff Sgt. Kyle E. Gese)