NEW YORK (CBSNewYork/AP) -- The owners of a 10-month-old French bulldog puppy that died on a United Airlines plane after a flight attendant told them to put the dog in the plane's overhead bin are speaking out.
For 11-year-old Sophia Ceballos and her mother, Catalina Robledo, Kokito was a part of the family.
"He was a really special dog. It's just sad the way he has to, just leave," Sophia said. "We took him everywhere we went."
On a United flight Monday night from Houston to New York, Robledo put her dog in a carrier. She struggled to put Kokito's carrier under the seat in front of her. That's when the family says a flight attendant insisted it go in the overhead bin.
"'It's a dog, it's a dog.' He can't breathe up there.' And she said, 'It doesn't matter, it still goes up there,'" Sophia said."She felt the dog and she put him up there."
United spokesman Charles Hobart said the flight attendant told the dog's owner to put the pet carrier in the overhead bin because the bag was partly obstructing the aisle. It is unclear why the carrier was not placed under a seat, he said.
The family says they heard Kokito barking for two hours. Then he stopped. They wanted to check on him, but couldn't.
"We tried, but there was a lot of turbulence and we weren't allowed to stand up," Sophia said.
When the flight was over, they found Kokito had died.
"My mom was crying. She was just screaming, she was looking at him," Sophia said.
A fellow passenger posted a photo of Kokito, saying "My heart broke with theirs as I realized he was gone."
United said Tuesday that it took full responsibility for the incident. In a statement, United called it "a tragic accident that should never have occurred, as pets should never be placed in the overhead bin."
" The dog was in a small pet carrier designed to fit under an airline seat. Passengers reported that they heard barking during the flight and didn't know that the dog had died until the plane landed at LaGuardia Airport.
Retired airline captain Denny Kelly says the pitch black overhead bin is dangerous for any live animal.
"There is no circulation at all in there," he said. "They're scared, their heart rate goes up and they use more oxygen. And if there's not enough oxygen in the first place, that just makes it worse."
The flight attendant told the airline she didn't know there was a dog inside the bag. She's been described as distraught over what happened.
Hobart said United is investigating the incident and talking to the flight attendant, whom he declined to identify. He said the airline refunded the tickets purchased for the dog owner and her two children and the fee that they paid to bring a pet on board — typically $200.
The cause of the dog's death was not immediately known. The spokesman said Chicago-based United offered to pay for a necropsy.
Last year, 18 animals died while being transported on United — there were six cases on all other U.S. carriers combined, according to the Department of Transportation.
On Wednesday, another mixup was adding to the backlash for the beleaguered airline after the Swindle family moved from Oregon to Kansas City. When they went to pick up their german shepherd after the flight, they were told he could very well be in Japan.
"All I can do is be hopeful that my dog is going to return home safely," Kara Swindle told CNN. "I don't know what else to do at this point."
The family is still waiting to find out of their dog was mistakenly sent to Asia.
(© Copyright 2018 CBS Broadcasting Inc. All Rights Reserved. The Associated Press contributed to this report.)
for more features.