U.S. Air Force Tech. Sgt. Joshua Foster, 81st Security Forces Squadron alpha flight chief, gives a briefing during an incident command change over during an active shooter exercise at Keesler Air Force Base, Mississippi, April 19, 2018. The wing inspection team had an active duty Air Force member simulate opening fire at the Levitow Training Support Facility in order to test the base’s ability to respond and recover from a mass casualty event. (U.S. Air Force photo by Kemberly Groue)