A 10-month-old French Bulldog has died after a flight attendant forced its owners to put it in the overhead locker for a three-hour flight from Houston to New York.
New York resident Maggie Gremminger was first to speak about the incident, saying the dog's owner didn't want to put the dog in the compartment, but the flight attendant was persistent.
"It was clearly a dog and while the customer was adamant about leaving it under the seat, the attendant pushed her to do so," she wrote on Twitter.
When the flight landed, the woman opened the overhead carrier and discovered the dog dead, apparently suffocated.
Distressed she sat on the floor of the plane and rocked back and forth holding the canine and crying as stunned passengers watched on.
Following reports of the dog's death being published, the family came forward and revealed the dog was only a 10-month-old puppy called Kokito.
He was travelling with his owner Catalina Castano and her two 11-years-old children.
Ms Castano's husband told Buzzfeed she wasn't comfortable putting the dog in the locker but the flight attendant assured her it was fine.
"My wife repeatedly asked her to let her keep the dog by her feet," he said.
"She then asked her if the dog would be OK. The flight attendant wouldn't let her keep Kokito by her feet and assured her that he would be fine. Witnesses can attest to that."
According to Mr Castano, she was unable to check on him during the flight due to turbulence.
United Airlines has taken full responsibility for the incident, refunding the family the cost of their tickets and the US$125 (NZ$170) pet carrier fee, The Guardian reports.
Mr Castano is still upset though, telling Buzzfeed nothing can replace their loss.
"Why is it that the flight attendant didn't know the airline in cabin pet policy?" he said.
"We feel we've lost a family member. Nothing can remedy that."