California: 34 dead or missing in dive boat fire

'Totally engulfed'

The surviving crew members sought refuge on a fishing boat moored a few hundred feet away, banging on the side to wake up Bob Hansen and his wife, who were sleeping onboard.

"When we looked out, the other boat was totally engulfed in flames, from stem to stern," Hansen said in an interview with The New York Times. "There were these explosions every few beats. You can't prepare yourself for that. It was horrendous."

Scuba or propane tanks on the Conception may have exploded in the fire, but that had not been confirmed, Brown said, adding it was unclear if there was an initial explosion that caused the fire.

After borrowing clothes from the Hansens, some crew members headed back toward the Conception to look for survivors but had no luck, Hansen said.

US Senator Dianne Feinstein, a Democrat who represents California, called for an investigation.

"It's inconceivable that with all the safety regulations we have in place today, a fire on a boat can lead to the loss of life we saw this morning," she said in a statement. "And we need to understand exactly how the crew was trained and, if they were awake and above-deck, why they were unable to alert or help rescue passengers."

Investigators said a single distress call from the boat reported the fire.

"It happened quickly enough so many people could not get off," US Coast Guard Lieutenant Commander Matthew Kroll told CNN.

The diving boat was chartered by Worldwide Diving Adventures, a Santa Barbara, California, excursion firm. It said on its website that the Conception was on a three-day excursion to the Channel Islands, and was due back in Santa Barbara on Tuesday morning.

The boat's owner, Truth Aquatics, referred queries about the accident to a joint media center. "This is still an ongoing search and rescue," it said.

Liu Yinmeng in Los Angeles contributed to this story.