PHILIPPINE SEA (Feb. 10, 2021) Gunner�s Mate 3rd Class Brayden Barthel, from Hagerstown, Md., simulates preparing a blast path for an improvised explosive device during an active shooter drill aboard the Arleigh Burke-class guided-missile destroyer USS John S. McCain (DDG 56). John S. McCain is assigned to Destroyer Squadron (DESRON) 15, the Navy�s largest forward-deployed DESRON and the U.S. 7th Fleet�s principal surface force. (U.S. Navy photo by Mass Communication Specialist 2nd Class Markus Castaneda)