A daughter of the Kentucky physician at the center of a global uproar over his forced removal from a United Airlines flight said Thursday that the family was "horrified, shocked and sickened" by the incident.

"What happened to my dad should never have happened to any human being, regardless of the circumstances," Crystal Pepper said at a news conference in Chicago.

David Dao, 69, suffered a concussion, broken nose and damaged sinuses and lost two front teeth when he was dragged off a flight Sunday to make room for United personnel, lawyer Thomas Demetrio said. He said Dao has been released from the hospital and is staying in a "secure" location.

A lawsuit will be filed at some point, and a hearing on preserving evidence is set for Monday in Chicago, Demetrio said. He also said United and other airlines have "bullied" customers for a long time.

"Dr. Dao, I believe to his great credit, has come to understand that he is the guy, he's the the guy to stand up for passengers going forward," Demetrio said.

In just a period of several days, the United Airlines incident has become a viral story, leading social media feeds and news broadcasts. It has opened up debates regarding customer service, civility and corporate policies.

Social media outrage rained down on the Chicago-based airline after videos emerged of Sunday night's violent confrontation on United Express Flight 3411 at Chicago's O'Hare Airport, drawing hundreds of millions of views around the world.

Demetrio called the video "rather disturbing." He said that neither United CEO Oscar Munoz nor other United officials have reached out to Dao. He also said he accepted Munoz's public apology — even though Demetrio called Munoz's appearance Wednesday on Good Morning America "staged."

"I think his PR people said 'We're taking a beating here,'" he said. "I think he was told to get out there."