180626-N-UX013-0557 MEDITERRANEAN SEA (June 26, 2018) Sailors enter a simulated smoke-filled space aboard the guided-missile destroyer USS Jason Dunham (DDG 109) during a general quarters exercise. Dunham is conducting naval operations in the U.S. 6th Fleet area of operations in support of U.S. national security interests in Europe. (U.S. Navy photo by Mass Communication Specialist 3rd Class Jonathan Clay/Released)