United Airlines already had a shaky reputation.

This won’t help:

More from the New York Post:

Maggie Gremminger, a passenger on a flight from Houston to New York’s LaGuardia Airport, uploaded a photo of the dog’s owners on Twitter. “I want to help this woman and her daughter. They lost their dog because of an @united flight attendant. My heart is broken,” reads the image caption.

The Points Guy reports that during their flight, an attendant insisted that the woman put her dog, which was held in a TSA-approved pet carrier, in an overhead bin for the rest of the flight.

Passengers heard barking during the flight, but didn’t learn that the dog had died until the flight was over.

“There was no sound as we landed and opened his kennel,” passenger June Lara writes in a Facebook post. “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.”

And lest you think this is some sort of sick hoax, a United spokesperson has confirmed the incident:

“We assume full responsibility for this tragedy and express our deepest condolences to the family and are committed to supporting them,” said the airline’s statement. We are thoroughly investigating what occurred to prevent this from ever happening again.”

More from CNBC:

United has faced public outcry after other animals have died on its planes. The airline said it transported 138,178 animals in 2017, more than any other airline, according to the Department of Transportation.

It had the highest rate of fatalities, too: 18 animal deaths. American and Delta each reported that two animals died on their planes last year. Those figures refer to animals that were transported in the cargo hold, not the cabin.

(Word to the wise: The Post’s article contains photos, so click at your own risk.)

Good luck coming back from this one, United.