Tech Sgt. Roger Dupuis, 11th Civil Engineer Squadron firefighter, brings pallets into the flashover identification trainer Aug. 28, 2012 at Joint Base Andrews, Md. A flashover is the near-simultaneous ignition of most of the directly exposed combustible material in an enclosed area. At Flashover identification training, firefighters learn the life saving skill of recognizing the indicators of flashover. (U.S. Air Force Photo by Senior Airman Perry Aston)