Joseph Thompson, 316th Civil Engineer Squadron fire protection assistant chief of operations, walks through the different layers of smoke in the live fire training building after live fire training March 5, 2010, at Joint Base Andrews Md. Live fire training is a necessary and indispensable tool for the 316th CES firefighters, which provides them with the ability to experience the heat and flames that can be found in a structure fire, but in a controlled environment. (U.S. Air Force photo by Airman 1st Class Perry Aston) (Released)