Members of the 28th Medical Group construct a decontamination tent during a Chemical, Biological, Radiological, Nuclear and Explosives major accident response exercise at Ellsworth Air Force Base, S.D., Oct. 21, 2011. Victims with simulated contamination were brought into the tent to be decontaminated, which provided medical personnel the opportunity to train to properly utilize the tent and save lives. (U.S. Air Force photo by Airman 1st Class Kate Thornton/Released)