RIP young men The seven Marines and one sailor who've been missing since their amphibious assault vehicle sank in the Pacific Ocean on Thursday are believed to be dead, ending an extensive 40-hour search-and-rescue mission. Officials with the 15th Marine Corps Expeditionary Unit announced early Sunday that leadership determined little likelihood the service members survived the accident. Sixteen troops with that unit were in the AAV during amphibious training near San Clemente Island when their vehicle began filling with water off San Diego's coast. Eight of the 16 escaped, and one of those Marines later died. Two others remain hospitalized in critical condition. "It is with a heavy heart, that I decided to conclude the search and rescue effort," Col. Christopher Bronzi, the 15th MEU's commanding officer, said in a statement. "The steadfast dedication of the Marines, Sailors, and Coast Guardsmen to the persistent rescue effort was tremendous."