United faces tough questions after what flight attendants did to a family's pet dog

United Airlines has another public relations disaster on its hands after passengers say that their flight attendants forced passengers to put their dog in an overhead bin, and the pet died on the flight.

Here's what happened

Various passengers on a United flight posted on social media about witnessing the altercation between flight attendants and a family of passengers that ended up with a dead dog.

Maggie Gremminger said she was distraught after seeing what happened and not speaking up for the doomed dog.

"Tonight I was on a plane where I witnessed a [United] flight attendant instruct a passenger to place her dog carrier (with dog) in the overhead compartment," she said in a tweet.

"The passenger adamantly refused but the flight attendant went on with the instruction," she explained. "At the end of the flight - the dog was found dead in the carrier."

"I am heart broken right now," she added. "I didn't question the flight attendant but could have. I assumed there must be ventilation as surely the flight attendant wouldn't have instructed this otherwise..."

She added a photo of the woman and her daughter who went through the ordeal.

Here's United's response

The airline responded after posts about the deceased dog went viral.

"This was a tragic accident that should never have occurred, as pets should never be placed in the overhead bin," the statement read. "We assume full responsibility for this tragedy and express our deepest condolences to the family and are committed to supporting them. We are thoroughly investigating what occurred to prevent this from ever happening again."

Their policy on dogs is clearly outlined on their website:

"A pet traveling in cabin must be carried in an approved hard-sided or soft-sided kennel," the policy reads. "The kennel must fit completely under the seat in front of the customer and remain there at all times…"

"A customer traveling with an in-cabin pet cannot be seated in the bulkhead or an emergency exit row," the policy concluded.

Here's a local news video about the incident: