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Coast Guard finds fuel leak caused engine fire on Carnival Triumph

The Carnival Triumph fire that knocked out power and left more than 4,000 passengers and crew stranded without air conditioning, hot food or working toilets was traced to a flexible fuel oil return line. NBC's Brian Williams reports.

The cause of the engine fire that left the cruise ship Carnival Triumph without power for five days was a leak in a fuel oil return line that sprayed onto a hot surface, the Coast Guard announced Monday.

Lt. Cmdr. Teresa Hatfield, head of the U.S. Coast Guard Marine Casualty Investigation Team, said the oil caught fire when it made contact with the hot surface. She said the suppression system kicked on immediately and that the ship’s crew “did a very good job” in responding.

 The fire is not suspected to have been caused intentionally.

During a teleconference with reporters Monday, Hatfield said the damage was contained to a relatively small area of the engine room. But because the oil burned at such a high temperature, crew members had to close off the room and could not immediately put out the blaze.

Hatfield deferred questions about when the fuel oil return lines were last inspected or why the damage had been so severe, saying only that the investigation is ongoing.

The Coast Guard has been with the vessel since it docked in Mobile, Ala., on Thursday and is conducting interviews with both passengers and crew. The service expects to complete the onsite investigation by the end of the week.

The Bahamas Maritime Agency is leading the investigation, but the Coast Guard and National Transportation Safety Board are leading the U.S. efforts.

The ship left from Galveston, Texas, on Feb. 7 for a four-day cruise that was to take passengers to Mexico. On the third day, the fire broke out, leaving the 4,200 passengers and crew with no power, a scarcity of food and only a few working bathrooms.

The final report on the incident could be six months away. Investigators are trying to determine why the fire disabled the ship.