U.S. Marine Corps Lance Cpl. Cole Vargasheathcock, left, and Cpl. Benjamin Adams, chemical, biological, radiological and nuclear (CBRN) defense specialists with Marine Wing Headquarters Squadron (MWHS) 3, 3rd Marine Aircraft Wing, function check a self contained breathing apparatus gear for a training exercise at Marine Corps Air Station Miramar, San Diego, Calif., April 30, 2013. The Marines took part in training to increase mission readiness and rehearse standard operating procedures and responses to CBRN scenarios. (U.S. Marine Corps photo by Sgt. Keonaona C. Paulo 3rd Marine Aircraft Wing Combat Camera/Released)