A Keller couple and 15 other Texans are suing Carnival Cruise Lines after a fire in the engine room of one of its vessels last month left them stranded on a powerless cruise ship in the Gulf of Mexico, exposing them to unsafe, unsanitary and unreasonable living conditions for five days.Seth and Michelle Tanner were among the 4,000 people aboard the Carnival Triumph when a fire broke out in the aft engine room on Feb. 10, knocking out the ships propulsion system, a lawsuit filed in federal court Thursday states. No one was injured and the fire was extinguished.But the ship drifted aimlessly off course until it was towed over the course of several days to Mobile, Ala. During those days passengers slept on the deck, used showers and plastic bags as toilets and couldnt avoid the pungent odors of smoke, sewage and diesel fuel.The lawsuit, filed in Dallas by the Turley Law Firm, accuses Carnival of failing to adequately maintain the cruise ship, to implement adequate emergency policies and to properly train its employees to handle the situation. The lawsuit seeks an unspecified amount of damages.When people pay money and place their lives in the hands of a cruise line, they have a right to expect safe and humane treatment, attorney Windle Turley said in a prepared statement. They received neither in this near disaster.The ship, which left Galveston on Feb. 7, was carrying 3,143 passengers and 1,086 crew members, was supposed to return on Feb. 11. Many of the plaintiffs didnt return to dry land until Feb. 14 or 15, according to the lawsuit.Carnival did not respond to an email request for comment. But, earlier this week, CEO and president Gerry Cahill said at a industry conference in Miami Beach that finding out what happened and how to learn from it is the companys highest priority.You can rest assured, its our highest priority. We will come up with some solutions that we can implement across our fleet, Cahill said. Since the incident the cruise line has offered passengers a full refund, $500 and discounts on future cruises.The National Transportation Safety Board has opened an investigation of the fire. After the ship was docked in Alabama, the cruise line acknowledged that the Triumph had been plagued by other mechanical problems in the weeks before an engine-room fire left it powerless.As the lawsuit was being filed in Dallas, Carnival was dealing with another stranded cruise ship, the Dream, which had encountered a technical issue with its backup emergency diesel generator in St. Maarten. There were brief interruptions to the elevators and toilets. Carnival was making arrangements to fly the passengers home.A family vacationFor the Tanners the Carnival cruise was supposed to be a vacation for them and their two children, Brandon, 8 and Rachel, 6.Brandon, who was diagnosed as a highly functioning autistic child according to the suit, had asked his parents to take him on a cruise for about a year, his father said. They were assigned to an inside cabin on Deck 6 that didnt have any ventilation.In an interview with the Star-Telegram, Seth and Michelle Tanner of Keller said the day of the fire they awoke to an announcement that simply said: Alpha Team to Engine Six. No alarms sounded, and there were no emergency lights to guide them out of their cabin.The rest of the trip was spent enduring long lines for food, sleeping on deck to escape the stink of toilets that no longer worked, and trying to entertain their children.Seth Tanner described how he and his wife took turns standing in line for food, eating ham sandwiches and yogurt that was beginning to spoil.By the time they got their food, it was time to stand in line for the next meal.The Tanners said they decided to sue Carnival because of a lack of communication and because the company did not properly handle the situation on board the ship after it lost power.When we were at sea, they [Carnival] cut corners where they felt they could, Seth Tanner said.Tanner described how passengers were not updated by crew members and how they often heard about developments through text messages from friends.