United Airlines has apologized to a 71-year-old grandfather who was pushed to the floor by an employee at an airport in Houston over a ticket dispute, leaving the man “there like a piece of garbage,” according to his attorney.

Footage of the incident at George Bush International Airport in July 2015 was broadcast late Tuesday by KPRC and shows Houston-based attorney Ronald Tigner being shoved to the floor by a male customer service rep just steps away from the ticket counter on July 21, 2015.

“This is just one of the most inhumane things I’ve ever seen in my life,” Tigner’s attorney, William Hoke, told the station.

The surveillance video shows Tigner motionless on the floor after the push, unconscious after hitting his head — and no other United employee decides to help the man, according to Hoke.

“He laid there lifeless for several minutes,” Hoke said. “Not one United employees [came] to check on him … They literally left him there like a piece of garbage.”

No United employees can be seen helping Tigner after the fall during the nearly three-minute surveillance footage. A passenger who was trained as a nurse bent down to assist Tigner about 50 seconds after he fell as nearby United employees “just watch,” KPRC reports.

A United employee later calls 911, but doesn’t tell the dispatcher that the elderly man was pushed or that he was unconscious.

“It’s astounding,” Hoke said. “It’s outrageous.”

Tigner is suing United Airlines and two employees, including the man who pushed him, identified as Alejandro Anastasia, for more than $1 million, alleging negligence in a dispute that Hoke says began over Tigner’s request for a new boarding pass since his was garbled. Anastasia laughed and cursed at Tigner, according to the lawsuit.

“Anastasia was looking at Mr. Tigner and started smiling and said, ‘Can’t you see we’re busy?’ and there’s no one in the vicinity of these two employees,” Hoke said. “And he tells Anastasia to wipe that smile off his face. That’s when Anastasia says, ‘I’ll kick your (expletive)’ and shoves Tigner to the ground.”

Anastasia was later charged with injury to an elderly individual, a felony, and was ordered to pay a fine. He was also ordered to wrote a letter of apology to Tigner and attend anger management sessions, KPRC reports.

United apologized for the incident on Tuesday, saying the footage shows “completely unacceptable behavior” by the now-former employee.

“The conduct shown here does not reflect our values or our commitment to treat all of our customers with respect and dignity,” United said in a statement to the station. “We are taking a thorough look into what happened here and reaching out to our customer to profusely apologize for what occurred and to make this right.”

The incident is the latest in a string of public relations nightmares for the airline industry, particularly United Airlines. Most recently, a classical musician sued the airline last week after she claimed she was barred from a flight with her centuries-old violin, causing her to miss the trip.

And in April, David Dao, 69, was booted from an overbooked flight and was injured by airport security officers while being removed in an incident caught on video that went viral, prompting United to later apologize and reach an undisclosed settlement.