HONOLULU — A U.S. Navy salvage ship is supporting underwater search efforts near the last known position of two helicopters that crashed off the coast of Oahu while carrying 12 Marines.
The Coast Guard says the ship arrived late Sunday from Pearl Harbor to support a Navy unit searching underwater with sonar and a remotely operated vehicle.
The unit's searches Sunday did not reveal any debris. The Coast Guard says anything located can help search and rescue planners narrow the search area.
Various agencies have been searching above water, below water and along the shoreline since late Thursday when a civilian reported seeing the aircraft flying and then a fireball.
There has been no sign of the 12 Marines missing since the two helicopters crashed, but officials say it is still possible that there are survivors.
Authorities say they have found several life rafts that were carried aboard the aircraft.
Coast Guard Chief Petty Officer Sara Mooers says she believes three life rafts have been recovered so far. She says some were inflated but it was unclear how they came to be inflated.
The search for any survivors of last week's crash is set to continue Monday.
Rescuers from various agencies have been searching around-the-clock since a civilian reported the crash late Thursday. The cause of the crash is not yet known.
Mooers says the helicopters also carry black boxes, although they have not been recovered.