Crew members who survived the California boat fire say they desperately tried to save passengers sleeping on the ship's lower deck

santa cruz boat fire
santa cruz boat fire

Ventura County Fire Department/Handout via Reuters

The crew of the Conception diving vessel, which went down in flames off the California coast, killing 34 people, told investigators how they tried in vain to save those trapped inside the burning ship.

Only five of the 39 people on board — all members of the crew — survived the disaster.

The Conception caught fire around 3:30 a.m. on Monday near Santa Cruz Island, northwest of Los Angeles.

Witnesses reported seeing the boat completely engulfed in flames. It is still unclear what caused the fire.

The boat's captain and four crew members escaped the wreckage by jumping on to a small boat. Authorities believe there are no other survivors.

The National Transportation Safety Board, the federal agency investigating the incident, described in a media briefing on Thursday the "harrowing story of the moments before the fire erupted."

According to NTSB board member Jennifer Homendy, investigators have been interviewing the survivors to try and understand what transpired.

One crew member told the NTSB that he awoke to noise from the galley area below where he was sleeping, and left his bunk to investigate. He discovered flames erupting from the area, which was above the guest's sleeping quarters.

Homendy said the ship's galley houses the kitchen, stove area, wiring and electrical systems, and gear charging stations, all of which could potentially have caught fire.

Crew members say they tried to get down a ladder to the guest's quarters, but could not get through because of the flames.

They then attempted to get to the main deck via the bridge of the ship, with one crew member breaking their leg in the process.

Read more: A boat was engulfed in flames off the California coast, claiming at least 20 lives. Here's what we know about the vessel.

Crew jumped from the boat as the flames grew

california boat fire
california boat fire

Santa Barbara County Fire Department via AP

Crew members then tried to open the double doors of the galley to try and help passengers escape, but were again blocked by fire.

After unsuccessfully attempting to break into a window at the front of the vessel, they decided to jump ship.

"At that point, due to heat, flames and smoke, the crew had to jump from the boat," Homendy said.

Two of the crew members told investigators that they swam back to the ship to get the skiff, a small utility boat, attached to the back of the vessel. Two other crew members were rescued and taken to a nearby vessel before they called for help.

"At that point, they left the vessel and returned back to the Conception in the skiff to try and rescue any survivors," Homendy said.

Did the crew make the right choices?

California boat fire
California boat fire

U.S. Coast Guard via AP

Homendy told reporters that investigators are currently putting together a timeline of the incident in order to determine if the right safety measures were taken by the crew.

They are also looking at the fire safety system in place on the boat, including smoke detectors and extinguishers.

Investigators are also examining whether there were sufficient escape routes on the vessel, and have said passengers were trapped below the deck with no way out.

"There was a stairwell to get down the main entry way up and down and there was an escape hatch and it would appear as though both of those were blocked by fire," Santa Barbara County Sheriff Bill Brown said Tuesday.

According to the LA Times, the US Coast Guard said the Conception passed all recent safety inspections.

Police called the accident "the worst-case scenario you could possibly have," because it happened at night in a remote area while everyone was asleep.

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