WASHINGTON, March 15 (Xinhua) -- United Airlines (UA) on Wednesday apologized for the death of a pet dog on one of its flights, saying the flight attendant gave the wrong instructions after mishearing a passenger.

"Our flight attendant did not hear or understand her (the pet owner), and did not knowingly place the dog in the overhead bin," a statement from the UA said in response to the pet owner's claim that the attendant gave the instructions after being notified of the dog's presence.

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

The incident took place Monday night on board a three-hour flight from the southern city of Houston to New York City. A carrier containing a French bulldog was on the ground sticking out into the aisle, and the owner was told to store it in an overhead bin. Upon arrival the dog died.

A witness, tweeting as Maggie Gremminger, said the bag had "clearly" contained a dog, but the attendant nevertheless pushed the owner to store it in an overhead bin.

UA has pledged to provide better care for pets on board its flights, taking measures such as labeling pet bags with bright colored tags.

The incident drew a spotlight on the UA's pet care record, which according to official figures is the worst in industry.

The U.S. Department of Transportation said 24 pets died or was injured last year while flying on U.S. carriers, 18 of which were on the UA flights.

As a company policy, the UA charges passengers 125 U.S. dollars to carry their pets on board.

In a separate incident, a family flying from the state of Oregon to Kansas Tuesday with their pet dog in cargo found upon arrival that the airlines had mixed up their dog with another. The dog that arrived in Kansas was destined for Japan, and the family's pet went on an unexpected Asia tour.

The UA later said it had located the family's pet and is in the process of uniting them.

The UA's reputation was tarnished last April when one of its passengers was brutally dragged off a plane to make room for its own crew. The airlines later settled a lawsuit with the passenger for an unknown amount.