Airman 1st Class Jeremy Harrison, 28th Civil Engineer Squadron emergency management journeyman, uses a multi-ray gas detector to test unknown substances for potentially hazardous properties during a training exercise at Ellsworth Air Force Base, S.D., Jan. 20, 2012. Emergency management trains for real-world scenarios by using an array of instruments to test and monitor a wide variety of hazardous material. (U.S. Air Force photo by Airman 1st Class Kate Thornton/Released)