Steve Rannazzisi confesses to Howard Stern

It was a lie that caused disbelief, cost him fans and ruined an endorsement deal.

Mid-September, comedian and The League star Steve Rannazzisi confessed that his old tale of working inside one of the World Trade Center twin towers during the September 11 terrorist attacks in New York was false.

His mea culpa came after the New York Times uncovered the lie. Rannazzisi, 37, tweeted his remorse, calling himself an "immature" young man who made a mistake, said he didn't understand why he said what he said 14 years ago, that he was "truly, truly sorry."

Although Rannazzisi's Comedy Central special still aired the following weekend, Buffalo Wild Wings severed its relationship with the comedian shortly after, pulling its ads featuring Rannazzisi from television.

This Tuesday, Rannazzisi went a step past his tweeted apologies, subjecting himself to Howard Stern's probing curiosity: Why tell such an offensive lie at all?

The comedian told Stern the story was a spur-of-the-moment mistake on stage that became nearly impossible to take back. "It wasn't calculated at all," he said on Stern's show, looking nervous. "It was as simple as sitting at the Comedy Store and everyone (being) like, 'Hey, you're from New York?' 'Yeah.' 'Were you just there? You were around?' 'Yeah, I was downtown.' 'You worked there?' 'Yeah, I did.'"

In the crowd were famous comedians like Pauly Shore and Andrew Dice Clay, who began to offer support. Rannazzisi says he didn't know how to take the tall tale back.

"You have like 15 seconds to go, 'Wait, hold on, stop, wait, I'm sorry, that's not true.' And if you pass that 15 seconds, now it becomes a thing where you're like — 'Now I have to be the guy who is very strange and weird and just said I lied about 9/11.'"

During the 40-minute interview with Stern, Rannazzisi also apologized again to people close to those who actually died on 9/11. "I know what I did was terrible," he said. "And I know that I hurt a lot of people," he told Stern. "In my heart I feel awful that my dumb mistake created this story that hit a wound that should never have been touched."