SEA OF JAPAN (Nov. 20, 2020) Fire Controlman 3rd Class Dondre Summers, from Waldorf, Md., simulates posting security for the backup reaction force during an active shooter training drill aboard the Arleigh Burke-class guided-missile destroyer USS John S. McCain (DDG 56). 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)