Leaking diesel fuel caused the engine fire that crippled the Carnival Triumph cruise ship for five days in the Gulf of Mexico, stranding more than 4,200 passengers amid sewage, garbage and little food, the Coast Guard said Monday.
The fuel leaked from the return line of the No. 6 engine and ignited when it hit an unspecified hot surface, Lt. Cmdr. Teresa Hatfield said during a telephone news briefing.
The fire was contained to a small area and the crew extinguished the blaze "immediately," said Hatfield, who leads the Coast Guard's Marine Casualty Investigation Team, which is based in New Orleans.
"They did a very good job," she said.
A diesel engine's high-pressure fuel injectors and injector pump use fuel as a lubricant during the combustion process, and the return-line hose transports the controlled excess amounts to the fuel tank to be reused.
The 14-year-old ship left Galveston, Texas, on Feb. 7 for a four-day trip to Mexico but was paralyzed by the fire Feb. 10. It was towed to Mobile, Ala., on Thursday night, and all passengers had disembarked by Friday morning.
Because the ship is registered, or flagged, in the Bahamas, Bahamian authorities are leading the overall investigation, assisted by the Coast Guard and the U.S. National Transportation Safety Board.
Investigators have interviewed passengers and crewmembers, and forensic analysis has been performed on the 893-foot ship. The Triumph was towed initially to Mobile Bay, then moved to nearby BAE Systems to fully assess the damage.
Hatfield said the Coast Guard expects to finish its on-board examination by the end of the week, and estimated that the investigation would take at least six months.
She said the Coast Guard would reinspect the ship before it's returned to service.