A dog has died after its owner was ordered to put it in an overhead locker during a United Airlines flight in the US.
The dog had been brought on board the flight in a small carrier designed to fit under a seat - but the woman carrying it was reportedly told to put it in the locker.
Passengers said they heard the dog barking during the flight from Houston to New York on Monday night.
But they did not know the dog had died until the plane landed at LaGuardia Airport, around three and a half hours later.
In a statement, United described the death as a "tragic accident that should never have occurred, as pets should never be placed in the overhead bin".
The woman, Catelina Robledo, had also been travelling with her daughter, 11-year-old Sophia Ceballos.
Passenger Maggie Gremminger wrote on Twitter after the flight: "I just flew into LGA and witnessed a United flight attendant instruct a passenger to put her dog bag in the overhead bin.
"It was clearly a dog and while the customer was adamant about leaving it under the seat, the attendant pushed her to do so.
"Myself and a fellow passenger felt like that was not a thing. I am not a flight attendant tho. Maybe they have air ventilation in there that I didn’t know about.
"I tried googling rules about pets on board but didn’t have ample time before takeout.
"At the end of the flight, the woman found her dog, deceased. She sat in the airplane aisle on the floor crying, and all of surrounding passengers were utterly stunned.
"I am disgusted and traumatized. Pets are family. How could a trained flight attendant instruct a passenger to place her dog in that bin.
"It was her job to understand the plane and it’s rules/limitations."
She aslo posted a picture of the mother and daughter, saying: "I want to help this woman and her daughter. They lost their dog because of an @united flight attendant. My heart is broken".
— MaggieGremminger (@MaggieGrem) March 13, 2018
Another passenger, June Lara, wrote on Facebook: "The flight attendants of flight UA1284 felt that the innocent animal was better off crammed inside the overhead container without air and water.
"They insisted that the puppy be locked up for three hours without any kind of airflow. They assured the safety of the family's pet so wearily, the mother agreed.
"There was no sound as we landed and opened his kennel.
"There was no movement as his family called his name.
"I held her baby as the mother attempted to resuscitate their 10 month old puppy.
"I cried with them three minutes later as she sobbed over his lifeless body. My heart broke with theirs as I realized he was gone."
Sophia said they had been told the dog would be in the way before it was put in the locker and the attendant "closed it like it was a bag".
She said that, after the flight landed, her mother had got up and got the bag. "She took him out and she's like 'Kokito, Kokito wake up!'".
United spokesman Charles Hobart said the flight attendant had told the dog's owner to put the pet carrier in the overhead locker because it was partly obstructing the aisle.
He said it was unclear why the carrier was not placed under a seat. The airline is investigating the incident.
Mr Hobart added that the dog owner and her two children had had their flights refunded, along with the fee they had paid to bring their pet on board.
The airline's own in-cabin pet policy states: "A pet traveling in cabin must be carried in an approved hard-sided or soft-sided kennel.
"The kennel must fit completely under the seat in front of the customer and remain there at all times."
The carrier made global headlines last year when a man was dragged off an overbooked flight after he refused to give up his seat.
Two security officers involved in the incident were discharged last October.
Additional reporting: IRN