The Carnival Triumph has lost propulsion, according to a statement by the cruise line.
A press release said that there was a fire in the engine room Sunday morning. It's now on emergency back-up power and will have to be towed to shore.
It happened as the ship was located about 150 miles off the coast of Mexico's Yucatan Peninsula.
None of the 3,143 passengers or 1,086 crew members were hurt. It left a port in Galveston, Texas on Thursday, February 7, and was set to return on Monday.
Carnival officials said the ship doesn't have propulsion and is waiting for tugboats to arrive to tow the ship to Progresso, Mexico. The cruise ship is expected to arrive there on Wednesday and passengers will be flown back to the United States.
A U.S. Coast Guard cutter is waiting next to the ship, Carnival officials said. The ship has been operating on generator power.
Passengers are sleeping on the deck. Some of the toilets on the ship are functional, but there is no hot water for showers.
Another carnival ship has been deployed to the location to provide passengers with additional supplies.