ELLSWORTH AIR FORCE BASE, S.D. -- (Right) Airmen 1st Class David Jack and Matthew Hung, 28th Civil Engineer Squadron emergency management journeymen, participate in an emergency management exercise, June 3. Both Airmen perform chemical, biological, radiological and nuclear detection and decontamination operations as well as emergency management command and control. (U.S. Air Force photo/Airman 1st Class Corey Hook)