Two soldiers were killed and three were injured when their Black Hawk helicopter crashed during a training exercise off Southern California’s coast, the Defense Department said Saturday.Staff Sgt. Vincent P. Marketta, 33, of Brick, New Jersey, and Sgt. Tyler M. Shelton, 22, of San Bernardino, California, died Thursday from injuries “sustained during an aircraft mishap while conducting aviation training,” according to a U.S. Army Special