United Airlines has taken “full responsibility” for the death of a passenger’s pet dog in the overhead bin of a Houston-New York flight on Monday, Reuters reported. The airline had the highest number of animal deaths – 18, against six deaths in all other airlines combined – in the United States in 2017.

The owner of the dog was flying with her children and the small dog on the United flight 1284. Another passenger, Maggie Gremminger, said on Twitter the woman had wanted to keep the dog in a small bag under her seat, but an attendant insisted that she put the animal in the overhead bin during the three-and-a-half-hour journey.

“At the end of the flight, the woman found her dog, deceased,” Gremminger wrote. “She sat in the airplane aisle on the floor crying, and all of surrounding passengers were utterly stunned.”

United called the incident “a tragic accident that should never have occurred, as pets should never be placed in the overhead bin”. A spokeswoman said the airline was investigating the incident.

The airline refunded the woman the cost of their tickets, including the $125 pet cabin fee.

In August 2017, a family had claimed that their dog died in the cargo hold during a flight from Houston to San Francisco. This was four months after a giant rabbit, believed to be the world’s largest, died on a transatlantic United Airlines flight. Simon, a 10-month-old continental giant rabbit who was 3 feet long, was found dead in the cargo.

The airline has faced several instances of bad publicity over the last year, including an incident when a doctor was injured after he was forcefully removed from an overbooked United Airlines flight.