The U.S. Coast Guard released aerial footage Tuesday of the early morning boat fire that left 34 dead after likely being trapped while sleeping below deck anchored off the Southern California coast on Labor Day.

FIRE BLOCKED ESCAPE FOR 34 ON BOAT OFF SOUTHERN CALIFORNIA COAST, INVESTIGATORS SAY

The video was taken by a Coast Guard MH-60 Jayhawk helicopter.  The crew was responding to the Conception boat fire off Santa Cruz Island early Monday.  The video shows billowing clouds of white smoke and flames engulfing the 75-foot vessel. The boat appears to tip backward as it begins to sink.

Rescue boats can also be seen making their way toward the boat, according to the footage posted by Fox 11 Los Angeles. A total of 39 people were aboard the Conception. Santa Barbara County Sheriff Bill Brown said Tuesday that the fire spread rapidly and flames blocked both exits of the lower deck, where passengers and one crew member were sleeping in tight quarters.

Five people—the captain and four crewmembers--- are known to have survived the fire. They were awake on the upper decks, jumped overboard and steered an inflatable lifeboat toward another ship anchored nearby.

The boat, owned by Santa Barbara’s Truth Aquatics, was chartered by Santa Cruz’s Worldwide Diving Adventures to lead a three-day diving excursion off the Channel Islands.

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Rescuers suspended their search for additional survivors Tuesday evening.

The National Transportation Safety Board is conducting an investigation into what caused the fire and if there were safety measures, such as fire extinguishers, on board. The agency will interview survivors, first responders and the companies involved in the diving trip, the Los Angeles Times reported.

A preliminary report could be released within 10 days of the incident.

Fox News’ Frank Miles and Hollie McKay contributed to this report.