ANCHORAGE, Alaska (AP) — Four crew members died Sunday and another was missing after a Seattle-based fishing boat sank in high seas off Alaska’s Aleutian Islands, the Coast Guard said.

The dead were among 47 crew members who abandoned ship after the 184-foot Alaska Ranger developed problems. Forty-two crew members were recovered safely, but a search was continuing for the missing person, said Chief Petty Officer Barry Lane.

The vessel started taking on water shortly before 3 a.m. after losing control of its rudder 120 miles west of Dutch Harbor, which is on Unalaska Island. Seas with up to 8-foot waves and 25-knot winds were reported at the time of the sinking, Lane said. The Coast Guard is investigating the cause of the accident, he said.

State environmental regulators were notified that the ship was carrying 145,000 gallons of diesel when it sank in deep seas, according to Leslie Pearson, emergency response manager for the Alaska Department of Environmental Conservation.

An oil sheen covered an area of a quarter mile by a half mile, Coast Guard spokesman Ray Dwyer said. Because of the strong winds, however, any cleanup effort is unlikely, although those conditions would disperse a spill much more quickly than calm weather, Pearson said.

Some of those on board the Alaska Ranger were heading to Dutch Harbor in a Coast Guard cutter and the sunken vessel’s sister ship, the Alaska Warrior. The vessel took part in the rescue operation along with two Coast Guard helicopters that were used to pluck crew members from life rafts, Lane said.

Other survivors were on board the Coast Guard cutter Munro, which remained at the scene to search for the missing crew member. Lane said the names of the dead would not be released until their next of kin had been notified.

A C-130 also remained to help search for the missing crew member.

Coast Guard Lt. Eric Eggan said it was unknown how or when the four died. The identities of the dead were unknown.

Chuck Harvey, a harbor officer on duty in Dutch Harbor, said his office was notified by the Coast Guard to clear a dock for its arrival, expected around 11 p.m. EDT Sunday.

The Coast Guard also told harbor officials to have an ambulance ready, but didn’t specify the degree or nature of any injuries, Harvey said.

“I figure there’s quite a bit of hypothermia going on,” he said.

The Alaska Ranger is owned by Seattle-based Fishing Company of Alaska. A man who answered the company’s phone Sunday afternoon declined to identify himself or comment. He said no one else was available to comment.

“Today, they’re all pretty much tied up,” he said.

Coast Guard Petty Officer Levi Read said the company had sent an insurance adjuster to Dutch Harbor, who was expected to arrive Sunday afternoon.