dog dies united airlines flight

Kokito, pictured in an undated handout photo, died on a United Airlines flight on March 12, 2018, after being placed in an overhead bin.
Tragedy struck on a United Airlines flight 1284 from Houston to New York City, when a dog in a TSA-compliant pet carrier died after a flight attendant allegedly forced its owner to store the animal and its carrier in an overhead bin for the duration of the four-hour Monday flight.

United has since claimed full responsibility for the "tragic accident" that killed Kokito, a black French bulldog, owned by Catalina Robledo of New York, who was traveling with her two children, ABC 13 reports. Robledo says that the airline has since contacted asking to settle the situation with money, which she says the situation is not about.

Passenger Maggie Gremminger told the New York Times that Robledo was insistent that the dog carrier should stay by her side, with no avail.

"The pet owner was very adamant that she did not want to put the pet carrier up above," Gremminger said. "She was saying verbally, 'My dog is in here, no, this is my dog.' The flight attendant, in response, really just continued to ask her to put it above because it was a hazard where it was, it was a safety emergency, someone could trip."

Gremminger said that she and her fellow travelers were horrified to learn the animal had died later in the trip, according to People.

"A stranger offered to hold her newborn while she sat on the floor, there in the airplane aisle. She was holding her dog and rocking back and forth. Her daughter was also crying," she told the publication about the scene following the discovery.

Gremminger further divulged that once Kokito was found dead, the flight attendant became "frazzled" and insisted she did not know there was a live animal in the carrier.

"I want to help this woman and her daughter. They lost their dog because of an @united flight attendant. My heart is broken," she wrote on Twitter, sharing a photo of the family who allegedly lost their dog.

Meanwhile, Robledo's daughter Sophia Ceballos told ABC that the flight attendant was fully aware that Kokito was in distress, as he barked through takeoff.

"While we were flying, the dog started barking and barking and there was no flight attendants coming. We couldn't stand up because there was a lot of turbulence so we weren't allowed to," Ceballos said, adding that attempts to inform the flight attendant of the severity of the situation were unsuccessful.

"She said, 'Oh, I'm sorry. I didn't know it was a dog. I thought it was a normal bag.' But we told her it was a dog, she's lying."

For their part, United's pet policy reads as follows:
"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."
United Airlines spokeswoman Maggie Schmerin returned Fox News' request for comment with the following statement:

"This was a tragic accident that should never have occurred, as pets should never be placed in the overhead bin. We assume full responsibility for this tragedy and express our deepest condolences to the family and are committed to supporting them," she said.

"We are thoroughly investigating what occurred to prevent this from ever happening again," Schmerin added.

The cause of death is not yet known, but, while the overhead compartments are not air-tight, lack of oxygen may have been a factor.

According to a report from the Department of Transportation, United had the highest number of animal deaths and injuries amongst all U.S. airlines in 2017, with 18 animals killed and 13 injured while flying through the airline's PetSafe cargo program.

The heartbreaking story comes weeks after United and Delta made headlines for tightening rules for flying with animals amid emotional support and service animal controversy.

United did not immediately return Fox News' request for comment on the updates to this story.