U.S. Marines and Sailors with the 15th Marine Expeditionary Unit and Essex Amphibious Ready Group medical staff prepare to transport a simulated wounded Marine during a mass casualty drill while participating in Composite Training Unit Exercise (COMPTUEX) aboard the USS Anchorage (LPD 23) off the coast of San Diego March 24, 2015. The medical staffs of the Essex ARG and 15th MEU train together to ensure they are prepared to handle crises, and maintain a high state of readiness. (U.S. Marine Corps photo by 1st Lt. Allison Burgos/Released)