Sergeant Jonathan Gleeson, left, and Sgt. Luis Maldonado, chemical, biological, radiological, nuclear defense specialists with 1st Marine Division, transport a mock casualty after a simulated explosion took place during Urban Shield 2014 in the San Francisco Bay Area, Calif. Urban Shield is a four-day event that brings together local, regional and federal law enforcement agencies to include U.S. military service members as well as detachments from allied nations to share tactics and best practices in crisis response.