This segment originally aired Nov. 18, 2016, on VICE News Tonight on HBO.

The Transportation and Security Administration was created 15 years ago this month, just two months after the 9/11 attacks. That was the day Frank Argenbright went from being the founder of the largest airport security firm in America to a villain.

Argenbright Security employed screeners at Dulles and Newark, where 9/11 hijackers boarded the planes that crashed into the Pentagon and into the field in Shanksville, Pennsylvania.

Frank Argenbright didn’t realize Argenbright Security might have been involved until a couple days later, he told VICE News correspondent Josh Hersh. They were accused of allowing highjackers onto the plane with boxcutters.

“What really broke my heart was the screeners calling me and saying, ‘Mr. Frank, you know what’s going on. Why don’t you tell them what’s going on?’ And I said, ‘I can’t say a word.'”

Argenbright had sold the company a few months before the attacks, and he wasn’t allowed to speak on the company’s behalf.

The backlash hurt his reputation, but he’s still in the security business. His latest project is a company that protects celebrities and billionaires, and trains corporations to respond to active shooters.