A military police officer with the Provost Marshal’s

A military police officer with the Provost Marshal’s Office guards the door to the gas chamber during a Chemical, Biological, Radiological, Nuclear and High-Yield Explosives (CBRNE) exercise aboard Marine Corps Air Station Miramar, Calif., May 18. The exercise revolved around the PMO, Miramar Fire Department, Explosive Ordnance Disposal, and Aircraft Rescue and Firefighting working together to identify and eliminate the threat of a simulated clandestine drug lab. (U.S. Marine Corps photo by Cpl. Alissa Schuning/Released)