Sailors assigned to the guided-missile destroyer USS O'Kane (DDG 77) perform a foreign object debris (FOD) walk down on the flight deck of the O'Kane during a crash and salvage/mass casualty drill as part of exercise Koa Kai 14-1 in waters near Hawaii. Koa Kai is a semiannual exercise that improves cooperation, readiness and the capability of forces to respond quickly to various crises, ranging from armed conflict to humanitarian assistance. (U.S. Navy photo by Mass Communication Specialist 2nd Class Dustin W. Sisco/Released)