Airmen in training from the 364th Training Squadron make their way around the track along Lt. Gen. Leo Marquez Boulevard North to kick off the 2018 POW/MIA 24-hour vigil at Sheppard Air Force Base, Texas, Sept. 20, 2018. Retired Air Force Lt. Col. John Yuill, a POW during the Vietnam War, briefly spoke to the Airmen before leading the first lap with 82nd Training Wing Vice Commander Col. Scott Belanger and Lt. Col. Shane Lensgraf, 364th TRS commander. (U.S. Air Force photo by John Ingle)