The fire that has put the Carnival Splendor out of service through mid-January has marine experts scratching their heads about how one engine fire could have blacked out a modern cruise ship carrying almost 5,000 people.
"Clearly, something that was supposed to work didn’t work," said Richard Burke, chairman of the engineering department at the State University of New York’s Maritime College. "The ship is designed with two engine rooms that are essentially duplicates, and they should have been able to provide power to the ship from the other engine room."
Burke said there were several possibilities as to what might have gone wrong.
"It could be there was equipment damaged in one of the engine rooms that was necessary to parallel the two power systems," he said. "If that’s the case, that’s a design error. Or, the equipment that was supposed to shift the load from one set of generators to the other didn’t work the way it was supposed to. The investigation will bring it out."
The investigation into what caused the fire and why its repercussions were so severe is being headed by the Splendor’s flag-state, Panama.
From the U.S., the National Transportation Safety Board and the Coast Guard are assisting, and Panama’s Maritime Authority will release all information on the investigation’s progress.
Carnival Cruise Lines said that a generator caught fire in the aft engine room about 6 a.m. on Nov. 8, preventing the transmission of electricity to the ship’s propulsion system and knocking out power to the ship’s main switchboard. That blacked out much of the ship’s hotel systems, including air conditioning, hot food service, phones and most of the interior lighting.
There was also no hot water, and for the first day, the ship’s toilets didn’t function.
Carnival said last week that damage to the ship was limited to the aft engine room and control rooms.
"The focus is on the No. 5 diesel generator in the aft engine room, but at this time the exact nature of the malfunction is still under investigation," said Carnival spokesman Tim Gallagher. "In our nearly 40-year history, this is the first time that we have had this sort of issue with a diesel generator. We don’t believe other vessels are at risk."
Still, Carnival and other cruise lines were taking no chances last week and were inspecting their ships’ engines and generators. 
Celebrity Cruises CEO Dan Hanrahan said he consulted with his hotel and marine groups.
"Once we learn more, we’ll further evaluate our systems," Hanrahan said. "We have redundant systems, so if there is a fire, we know we will still have power."
He was quick to add that Carnival had succeeded in meeting any cruise ship’s main objective: safely returning passengers to port.
"Carnival achieved that," Hanrahan said.