Defense Secretary Ash Carter, right, shakes hands with retired Air Force Chief Master Sgt. William Tippins during a POW/MIA ceremony at the Pentagon, Sept. 16, 2016. Tippins was a prisoner of war for 18 months during World War II. National POW/MIA Recognition Day is observed on the third Friday in September and honors those who were prisoners of war and those who are still missing in action. DoD photo by Air Force Tech. Sgt. Brigitte N. Brantley