With the Coast Guard search for the fishing vessel Destination suspended, the focus is now turning to solving the mystery of what happened to the 95-foot Bering Sea crabbing boat and its six crew members.

Investigators trying to determine what caused the deadliest Bering Sea crabbing disaster in more than 20 years will have little to go on: Hardly a trace of the Destination or the six men aboard has been found.

The 95-foot boat disappeared in the waters just off St. George island Saturday morning. The last two major vessel losses in the Bering Sea crab fleet happened in roughly the same area — within about 100 miles of the Pribilof Islands of St. George and St. Paul.

On Tuesday, the Coast Guard was in the process of launching an investigation into what happened to the F/V Destination, said Scott Wilbert, a civilian who is the head of the Coast Guard's Alaska commercial fishing vessel safety program, based in Juneau. The National Transportation Safety Board will also likely investigate the accident. 

The timeline on when a final report would be issued on the sinking is unclear. Who will be on the investigation team "is being determined as we speak," said Wilbert.

But with no boat, survivors or witnesses yet found, the inquiry may rest on what's known about the boat and its crew before it left Dutch Harbor for what was supposed to be a voyage to St. Paul to begin the snow crab season.

"One of the first things they would do is look into the vessel's history and our interactions with it," Wilbert said.

It's likely investigators will look at icing, a danger for boats on the Bering Sea during the winter crabbing season, as well as other ways the boat could have become destabilized and rolled, said Jack Molan, a veteran Bering Sea fisherman who now works as a photographer and public speaker in Bend, Oregon, and who fished alongside the Destination for years.

But it may be hard to ever know for sure what happened.

"There will always be some things that are a mystery," he said. "When boats go down without a mayday call and there's nothing found — it's hard to know what the heck happened."

The blue-and-white Destination boat operated out of Sand Point, but was registered in Seattle. Molan called the captain of the boat, who has not been officially identified, a "fine guy who was extremely experienced."

"Some boats are always looking for help. And some boats are never looking for help, those are the boats that you want to be on," said Molan.

The Destination was one of those boats that was never looking to hire, he said.

Commercial fishing in Alaska, especially the Bering Sea crabbing industry, is much safer than it once was.

In the 1990s, Bering Sea fishing earned its "Deadliest Catch" reputation: 73 crew members in the fleet were killed during that decade, from vessel sinkings, falls overboard or on-board injuries, according to data from the National Institute for Occupational Safety and Health.

In 1996, the Pacesetter, a 127-foot Bering Sea crab boat, capsized in a storm about 60 miles south of St. George island. None of the seven people onboard were ever recovered.

The last time a Bering Sea crabbing boat went down with a major loss of life was January 2005, when the Kodiak-based Big Valley sank in frigid water about 70 miles off St. Paul while working the winter snow crab fishery.

Five people were killed. One deckhand survived. In that case, a Coast Guard inquiry determined the boat was carrying far too much weight and the captain had overloaded the vessel in the past.

From the winter 2005-2006 season until the end of the 2012-2013 season, only one person was killed, by a fall overboard, according to federal occupational safety data.

A "revolutionary change" in culture coupled with changes in fisheries management and new safety regulations has made the Bering Sea crab fishery — and commercial fishing in general in Alaska — much safer, said Jerry Dzugan, the head of the Alaska Marine Safety Education Association, a Sitka-based nonprofit.

Incidents where a boat goes down and all hands are lost are "much rarer," he said. But, he said, risk can never be eliminated from work on the water.