A dog has died on a flight after its owner was forced to put it in an overhead bin.

The incident happened on a United Airlines flight between Houston, Texas and New York on Monday. In a statement, the airline said it accepted full responsibility for the animal's death. The French Bulldog was travelling with its owners, a woman and her children, in an airline-approved pet carrier case, according to the BBC. Fellow passengers claim the woman was pressured by a member of cabin crew to put the case in the locker above her seat for the three-and-a-half-hour flight. The stewardess later claimed she didn't know the dog was in there. Maggie Gremminger tweeted after the flight landed to share what had happened.

I want to help this woman and her daughter. They lost their dog because of an @united flight attendant. My heart is broken. pic.twitter.com/mjXYAhxsAq

— MaggieGremminger (@MaggieGrem) March 13, 2018

She told travel website One Mile at a Time that the passenger was repeatedly told to put the dog in the storage compartment. "The passenger adamantly pushed back, sharing verbally that her dog was in the bag," said Maggie. "The flight attendant continued to ask the passenger to do it, and she eventually complied. "By the end of the flight, the dog was dead. The woman was crying in the airplane aisle on the floor." United Airlines has said it is investigating the dog's death. "This was a tragic accident that should never have happened," it said in a statement. "We assume full responsibility for this tragedy and express our deepest condolences to the family and are committed to supporting them. "We are thoroughly investigating what occurred to prevent this from ever happening again. Pets should never be placed in the overhead bin," the statement added. United Airlines has a poor record of transporting animals, the Guardian reports. It had the highest number of animal deaths for any US carrier in 2017 - 18 were killed and 13 injured in while in transit with United last year, according to the US Department of Transport.