With no air conditioning, running water, lights or hot food, the 627 passengers were forced to sleep on deck in the stifling heat until the liner was towed into Seychelles capital Victoria yesterday.
One of the Costa Allegra's three diesel generators caught fire on Monday and although the blaze was extinguished within an hour two more generators in the engine room then failed, the ship's captain, Niccolo Alba, told a news conference.
Alba said a general emergency was declared when the generator caught fire, the lifeboats were prepared and passengers were ready to abandon ship as the liner drifted in the Indian Ocean, where Somali pirates roam.
"It was terrible, as you can imagine. Hygiene conditions were absolutely deplorable. I have some photos that show the state of the toilets. We stayed for three days without electricity, it's very difficult to live in such conditions, especially in such heat," one passenger told Reuters Television.
Alba said two people had fallen in the dark and hurt themselves, but he denied an earlier report from a Seychelles health ministry official that six people had broken limbs.
"They were able to put the fire out and from that point on, it was just a matter of inconvenience, not having enough food, not being able to rest well at night...the heat is unbearable, so we had to spend most of our nights on the top deck of the ship," said another passenger.
More than half the passengers took up the offer of a seven or 14-day holiday on the archipelago from the ship's owner Costa Cruises, the same company whose giant liner Costa Concordia smashed into rocks off Italy in January.
At 29,000 gross tonnes, the ship is considerably smaller than the huge Costa Concordia which capsized, killing at least 25 people.
A team from Costa Cruises, a unit of the U.S. cruise line giant Carnival Corp. , boarded the Costa Allegra on Wednesday to arrange hotel accommodation and onward flights for the passengers. It said more than 600 airline seats and 400 rooms had been reserved.
A small generator was installed in the crippled vessel, but was only powerful enough to run its auxiliary communication system, not the air conditioning or cooking systems.
With no lights working on board, the company said it had dropped hundreds of torches onto the ship to help passengers find their way around at night.
A passenger from Germany praised the crew, saying they had tried their best to make those on board comfortable.
Another passenger from the Indian Ocean island of Reunion said he felt tired and dirty and had been afraid of pirates, but there was never any shortage of drinking water or sandwiches.
Norbert Stiekema, executive vice-president at Costa Cruises, told the news conference that all passengers were offered the option of a holiday or a flight home, and that all outstanding bills on the ship had been cancelled.
The passengers were met in Victoria by ambulances, a Red Cross medical team and a fleet of small buses to take them to hotels on the country's main island of Mahe.
One woman was rushed into an ambulance and another had to be supported as she walked off the ship.
The passengers, including four children, are from 25 nations. The largest contingents are 127 from France and 126 from Italy. There were also 38 Germans, 31 Britons, 13 Canadians and eight Americans.
The Costa Allegra left Diego Suarez in Madagascar on Saturday and, sailing northeast, had been due to dock in Mahe on Tuesday. While 376 passengers opted to stay on in the Seychelles, others had had enough
"I am no longer in the mood for a holiday. I want to go home as soon as I can," said another passenger.
