Steve Rannazzisi has shared some sordid tales on his friend Ari Shaffir’s Comedy Central series, This Is Not Happening, but one of his most-told tales about the Twin Towers was too tall for the truth.

In a dramatic turnabout, just a few days before his new stand-up special “Breaking Dad” debuts on Comedy Central on Sept. 19, Rannazzisi has come clean about where he was and where he wasn’t in New York City on Sept. 11, 2001.

“I was not at the Trade Center on that day,” he said in a statement provided by his publicist, Matthew Labov. “I don’t know why I said this. This was inexcusable. I am truly, truly sorry.”

UPDATE Comedy Central is weighing whether to even air Rannazzisi’s special now on Saturday, issuing this statement Wednesday: “We just learned about this last night. We are very disappointed to hear about Steve’s misrepresentations and are currently determining how we will move forward.”

In multiple interviews over the past decade, however, he had described working for Merrill Lynch at the World Trade Center that day, and witnessing the terrorist attacks from the street outside. He actually worked in Midtown. Two years ago, Rannazzisi had given me this answer about his decision to leave NYC for Los Angeles: “I had always wanted to go to L.A. I always felt like that was the right move for me, for acting, for film and television. I kind of got the bug doing stand-up while I was in New York, but I thought, you know, I want to do the Groundlings as well. I want to go to The Comedy Store and get my foot in there. And then, my job was sort of affected by 9/11, so my wife and I – she was my girlfriend at the time – thought that was the right time after 9/11. We had a good severance package, and unemployment benefits. Let’s go now. Let’s try and do this thing now. So we moved a month-and-a-half after that, and as soon as we got there, I got a job at The Comedy Store, that’s where I met Ari. I started doing The Groundlings, kind of simultaneously, and just built from there.” I’d linked to his Sklarboro Country podcast with the Sklar Brothers to let readers listen to Rannazzisi’s full 9/11 account.

Which now sounds reminiscent of NBC News anchor Brian Williams exaggerating his own proximity to war in TV interviews over the years. Those tall tales cost Williams his job, with a suspension and later demotion to MSNBC (this fall).

Rannazzisi just released a series of Tweets @SteveRannazzisi to apologize and clarify his story.

“As a young man, I made a mistake that I deeply regret and for which apologies may still not be enough. After I moved with my wife to Los Angeles from New York City in 2001 shortly after 9/11, I told people that I was in one of the World Trade Center towers on 9/11. It wasn’t true. I was in Manhattan but working in a building in midtown and I was not at the Trade Center on that day. I don’t know why I said this. This was inexcusable. I am truly, truly sorry.

For many years, more than anything, I have wished that, with silence, I could somehow erase a story told by an immature young man.It only made me more ashamed. How could I tell my children to be honest when I hadn’t come clean about this?

It is to the victims of 9/11 and to the people that love them–and the people that love me–that I ask for forgiveness. It was profoundly disrespectful to those who perished and those who lost loved ones. The stupidity and guilt I have felt for many years has not abated. It was an early taste of having a public persona, and I made a terrible mistake.”

His new hour, “Breaking Dad,” on Comedy Central includes an act-out gag in which he fakes an injury to avoid pumpkin picking with his wife on NFL Sundays. The rest of the hour he tries to prove he’s still a cool dad, whether he’s coaching his sons in Little League or visiting a gun shooting range.

He brings his two young sons and his wife onstage for his encore to introduce them to the audience.

“Steve Rannazzisi: Breaking Dad,” premieres on Comedy Central on Saturday, Sept. 19 at 11:00 p.m. ET/PT.