* Company says some toilets working
* "Condiment burgers" and cold onion sandwiches for dinner
* Plastic 'biohazard' bags serve as improvised toilets
By Kaija Wilkinson
MOBILE, Ala., Feb 13 (Reuters) - More than 4,220 people aboard the stricken cruise ship Carnival Triumph on Wednesday faced one more night of what some have described as hellish conditions before their expected arrival in Alabama, even as the company said the situation was improving.
The 893-foot (272 meter) vessel has been without propulsion and running on emergency generator power since Sunday, when an engine room fire left it adrift off Mexico's southern Yucatan Peninsula. It is being hauled by tugboats to Mobile, Alabama, where it is due to arrive no later than Thursday.
Vance Gulliksen, a spokesman for the ship's operator Carnival Corp, said on Wednesday that conditions aboard the Triumph had improved, even as passengers described dire circumstances on board.
Some passengers who contacted relatives and media earlier this week before their cellphone batteries died reported a horrific situation aboard the ship, saying it was awash in raw sewage from overflowing toilets and running short on food and water.
Kim McKerreghan told CNN news network that her husband and young daughter, who are on board the ship, said in a call on Monday that passengers were being forced to defecate in plastic bags due to a shortage of working toilets and that meals consisted of sandwiches with only condiments or onions.
Nick Ware, whose mother is among the Triumph passengers, told the network, "Once the meat for the burgers ran out, they were basically just eating condiment hamburgers. Just, you know, whatever condiments they could get on a bun."
He said some passengers had been instructed to use "red biohazard bags" as makeshift toilets on Monday.
The ship left Galveston, Texas, last Thursday carrying 3,143 passengers and 1,086 crew and had been due to return there on Monday.
Gulliksen said a technical team on board had succeeded in gradually restoring auxiliary power to operate some basic hotel functions.
"Public and cabin toilets are operational in certain sections of the ship and some power in the Lido dining area is providing for hot coffee and limited hot food service," he said.
He did not elaborate on the number of working toilets for the 4,229 people but said the ship had cold running water and that three Carnival ships had rendezvoused with the Triumph to provide additional supplies and meals.
The U.S. National Transportation Safety Board said on Tuesday that it had launched an investigation into the cause of the Triumph fire. But it said the Bahamas Maritime Authority was the primary investigative agency, since the ship was a Bahamian flagged vessel.
Carnival, the world's largest cruise company, has apologized and said passengers would receive a full credit for the cruise plus transportation expenses and a future cruise credit equal to the amount paid for this voyage.
Difficulties on board the Carnival Triumph occurred a little more than a year after 32 people were killed when the Costa Concordia, a luxury cruise ship operated by Carnival's Costa Cruises brand, was grounded on rocks off the Tuscan island of Giglio in Italy.
Shares in Miami-based Carnival closed down 4 percent at $37.46 Wednesday on the New York Stock Exchange after the company said voyage disruptions and repair costs related to the Carnival Triumph could shave as much as 10 cents per share off its second-half earnings.