Three empty life rafts were recovered in the search for 12 missing marines off the coast of Hawaii, the Coast Guard said in a statement on Monday. Search and rescue crews also discovered a fourth life raft, but workers were still trying to retrieve it. “There is no indication from the sightings that any survivors have been aboard any of the life rafts,” the statement said. The 12 marines went missing after two CH-53 Sea Stallion helicopters collided during a nighttime training mission off the Hawaiin coast. The development comes as the search entered its fourth day and one day after a Coast Guard official reported that “debris” had been recovered off the north shore of Oahu.