Tech. Sgt. Steven Groff, 28th Security Forces Squadron flight chief, and Airman 1st Class Christopher Dominguez, 28th SFS response force member, prepare to search a building on the flightline during a training exercise at Ellsworth Air Force Base, S.D., Feb. 10, 2016. Defenders must be ready at a moment’s notice for any situation that may occur, whether it be a drunken driver or an active shooter. (U.S. Air Force photo by Airman 1st Class Denise M. Nevins/Released)