The plaintiffs, Kathleen Hanni of Napa, Calif., and Catherine Ray of Fayetteville, Ark., want courts to certify the cases as class actions covering thousands of passengers stranded on American flights when severe weather temporarily shut Dallas/Fort Worth airport on Dec. 29, 2006, forcing flights to go to other airports.

Both women's flights were diverted to Austin. The complaints allege passengers suffered hunger, thirst, illness, emotional distress and financial losses when American (AMR) failed to supply the planes with food or water, empty the toilets or let passengers off.

The complaints were filed in state courts last week in Napa and Fayetteville.

American spokesman John Hotard declined to comment on the complaints, saying he had not seen them. He noted that since December 2006, American has implemented new procedures designed to prevent recurrences. Those include a guideline limiting ground delays to four hours when possible and letting passengers deplane when it is safe to do so.

Hotard said a record number of American flights were diverted Dec. 29, 2006, because of severe thunderstorms.

"That was our largest weather disruption, ever, and we handled it the best we could," he said. "I think we have fixed the problem and lawsuits are not necessary."

The cases come amid public and congressional calls for stronger regulation of how airlines treat customers. A New York law that would penalize airlines for holding passengers on planes without food and water took effect Tuesday, and the U.S. House of Representatives has passed a bill that would force airlines to provide essential needs to stranded fliers.

"We're looking for justice for the passengers," Hanni said in an interview Monday.

After her experience, she founded Coalition for an Airline Passengers' Bill Of Rights.

Class actions against airlines when no crash is involved are unusual but not unprecedented. In 2001, Northwest Airlines (NWA) settled a similar class-action lawsuit by paying $7.1 million to passengers held aboard grounded planes in Detroit for up to eight hours during a January 1999 blizzard.

Aviation lawyer Jon Schneider of Boston said proving false imprisonment will be "a stretch."

"The passengers voluntarily boarded the plane," he said. "They will have to demonstrate the airline was completely unreasonable. I think the airline's response will be that they didn't do it intentionally."

Hanni's complaint says the captain told passengers American's management would not allow the plane to go to a gate. It says that after 9 hours 17 minutes, the captain declared an emergency so he could go to a gate.

During the delay, passengers received only a bag of pretzels and a cup of water, and the plane's toilets overflowed, it says.

Hanni said American later gave her a $500 coupon for a future flight. She said she hasn't used it.