(Recasts with Department of Transportation probe and senator's planned bill; adds quotes)
March 14 (Reuters) - United Airlines faced fresh backlash on Wednesday over a puppy that died in-flight after a cabin attendant ordered it stowed in an overhead bin, and the U.S. Department of Transportation said it was examining the events that led to the French bulldog's death.
U.S. Senator John Kennedy, who earlier on Wednesday sent a letter to United Airlines President Scott Kirby demanding information on the high number of animals that have died in the carrier's care, wrote on Twitter that he planned to file a bill on Thursday that would prohibit airlines from putting animals in overhead bins.
"Violators will face significant fines. Pets are family," he wrote.
Kennedy, in his letter, said United's "pattern of animal deaths and injuries is simply inexcusable." He cited figures from the Transportation Department that of the 24 animals that died on U.S. carriers last year, 18 were on United flights.
The actions came after a United flight attendant insisted that the bulldog's owner, Catalina Robledo, put her pet, which was in a dog carrier case, in an overhead storage bin during a 3-1/2-hour flight from Houston to New York on Monday.
Robledo's 11-year-old daughter, Sophia Ceballos, in an interview with CBS, recounted her reaction when the attendant ordered that the dog carrier case be placed in the overhead bin.
"I was like 'It's a dog, it's a dog. He can't breathe there,"' Ceballos told CBS. "(The flight attendant) was like 'it doesn't matter."'
The family told CBS they heard the puppy, named Kokito, barking for two hours during the flight before he went silent. The family said they were unable to check on the dog because of turbulence that forced them to stay seated.
The Department of Transportation "is looking into the circumstances surrounding the recent death of a pet onboard a United Airlines flight," an agency spokesman said on Wednesday.
The department "is in contact with the U.S. Department of Agriculture, the agency that enforces the Animal Welfare Act and handles complaints about alleged animal mistreatment," the spokesman said.
The Federal Aviation Administration is also looking into the incident and will "review the airline's investigation," FAA spokesman Greg Martin said.
United said that despite the puppy owner's telling the flight attendant that there was a dog in the carrying case, the flight attendant either did not hear or did not understand that there was a pet in the bag, and "did not knowingly place the dog in the overhead bin."
United said it had concluded its investigation into the matter.
The $125 fee that Robledo paid for her dog to fly in the cabin and the cost of the airfare have been refunded.
Several high-profile incidents of animal deaths and misplacements on United flights have plagued the airline over the last year, including the death of a giant rabbit on one of its flights last July and a dog that died in a plane cargo hold in August.
The airline's animal troubles compound a public relations nightmare tracing back to last spring when a man was dragged from his seat and down the aisle of a parked United plane in order to make room for an airline employee.
United said that by next month, it would issue brightly colored bag tags to passengers traveling with in-cabin pets to help flight attendants easily identify the animals.
(Reporting by Alana Wise Additional reporting by David Shepardson Editing by Leslie Adler)