Oregon Marine among the missing in Marine Corps helicopter crashes off Hawaii coast

OAHU NORTH SHORE, HAWAII  -  The search continues for 12 missing marines after what authorities suspect was a mid-air collision between two Marine Corps helicopters near Hawaii.

Rescuers are searching by air and combing local beaches for any sign of debris.

The Marines released the names of the missing, and it includes an Oregon man.

Lance Corporal Ty Hart, 21, is from Aumsville, Oregon, just outside of Salem.

The Coast Guard is staying optimistic, stressing its still conducting a "search and rescue" mission.

But factors beyond their control such as large surf and strong and shifting currents are making it a tough one.

Crews have covered more than 5,000 square nautical miles searching for the 12 missing Marines.

It’s a search that grows more difficult by the hour.

"When you talk about searching from the air, you're a couple hundred feet off the ground,” said U.S. Coast Guard Lieutenant Scott Carr.  “Seeing a person in the water, the only thing that would be appearing above them, above the water, would be their head, maybe their shoulders."

Search crews continue to find what they call debris consistent with the type of helicopter involved in the crash, but so far no sign of the missing Marines.

"There have been a couple life rafts found,” Carr said.   “There's been a lot of debris found.  Unfortunately, we have not found any survivors.”

The Coast Guard says the high surf is just one challenge.

There are also ocean currents which may have sent survivors or debris several miles from the crash area.

To deal with that, the Coast Guard has been dropping buoys to help determine the best places to search.

"We can drift people in a life raft. We can drift various types of things that you might be looking for.  That helps us kind of determine where, based on the currents, where things are going,” Carr said.

As for how long the search will continue, the Coast Guard says there isn't a timetable at this point.

"At this point, it's still a search and rescue mission.  And the Coast Guard and our partner agencies are going to continue to search and maintain hope that we'll be able to find these Marines and bring them home to their families,” he said.

The Coast Guard warns anyone who finds debris to treat it as hazardous material.