LOS ANGELES — LOS ANGELES (AP) — All six crew members were asleep aboard a scuba diving boat off the Southern California coast — in violation of Coast Guard rules — when a fire broke out in the middle of the night, killing 34 people who were trapped in a bunkroom below the main deck, U.S. authorities said Thursday.

The National Transportation Safety Board's preliminary report said five crew members, including the captain, were sleeping in their quarters behind the wheelhouse on the second deck of the boat and another was asleep below deck with the passengers when the fire started.

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The five above board survived and the other, a 26-year-old woman who had recently started working on the Conception, was killed.

The cause of the Sept. 2 blaze has yet to be determined. Crews raised the wreckage of the burned-out boat Thursday from waters off Santa Cruz Island where the vessel was anchored the night of the tragedy. The island is northwest of Los Angeles and about 20 miles (32 kilometers) from the mainland.

Boats like the Conception are required to have a roving watchman while passengers sleep, Coast Guard Petty Officer Mark Barney said. Crew members can take shifts as long as someone always is awake and aware of what's happening on the vessel and in the waters around it.

"A roving watch is someone who is readily available to respond to emergencies at sea," Barney said.

Federal authorities are conducting a criminal investigation and could bring charges under a statute known as seaman's manslaughter.

The law was enacted during the 19th century to punish negligent captains, engineers and pilots for deadly steamboat accidents that killed thousands.

Douglas Schwartz, an attorney for the Conception's owner, Truth Aquatics Inc., said in a statement that a crew member was awake shortly before the fire, which started around 3 a.m. He said the crewman checked "on and around the galley area" around 2:30 a.m. The first mayday call from the captain was transmitted at 3:14 a.m.

He also touted the company's safety record, noting it passed "every single annual Coast Guard inspection for the last 45 years, while hosting 450,000 divers on 1.3 million dives."

Truth Aquatics Inc. filed a lawsuit last week in U.S. District Court under a pre-Civil War provision of maritime law aimed at limiting its liability.

The victims on the Conception were a diverse collection including a girl celebrating her 17th birthday with her parents and a friend, a marine biologist who was leading the three-day scuba diving excursion, an Indian-born dentist and her husband from Connecticut, an environmental scientist and a professional photographer.

The last of the 34 bodies was pulled from the water Wednesday. It's believed all died from smoke inhalation.

The Coast Guard has issued additional safety recommendations in the wake of the tragedy, such as limiting the unsupervised charging of lithium-ion batteries and the use of power strips and extension cords.

The NTSB report provided few additional details and noted that investigators have only interviewed three of the five surviving crew members, who said no mechanical or electrical issues had been reported prior to the fire.

NTSB spokesman Eric Weiss said the Coast Guard asked their investigators to postpone the remaining crew interviews pending an investigation.

Attorney Michael Lipman, who represents boat captain Jerry Boylan, said he does not believe his client spoke with the NTSB. Lipman refused to discuss any facts in the case, whether he had spoken with any federal agencies or whether he advised his client not to speak with authorities.

"I would say that he's emotionally devastated," Lipman said. "It's a tragedy."

The NTSB report did not mention potential charges, which would be part of the criminal probe.

An attorney who represented a Maine lobster boat captain charged in the deaths of two crew members who fell overboard when his boat flipped in high seas said he suspects prosecutors reviewing the information will ask if there was a watchman and, if not, what the captain had said or done.

"No watch? A boat that far offshore?" Michael Turndorf asked. "I think that fits the statute. I would be surprised if those are the real circumstances that somebody doesn't get charged."

The NTSB says one of the crew members on the upper deck awoke to a noise and saw flames rising from the middle deck. He alerted the rest of the crew as the captain issued a panicked mayday call to the Coast Guard.

The crew, finding the ladder to the main deck on fire, jumped down — one breaking a leg in the process. They tried to reach the others through a window but couldn't open it. They were forced to jump overboard when they became "overwhelmed by smoke."

The captain and two crew members swam to the vessel's stern and reboarded the boat, according to the NTSB report. They opened the engine room's hatch but didn't find any fire. With other access routes blocked, they launched the boat's skiff and picked up the other two crew members and went to a nearby anchored boat.

Once aboard, the captain continued to send mayday calls as two crew members returned to the Conception to search for survivors near the burning wreckage.