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.