Actor and comedian Steve Rannazzisi, 37, is under fire after admitting Tuesday that he has been publicly lying about what happened to him during the terrorist attacks on the World Trade Center Towers that occurred Sept. 11, 2001.

In a 2009 interview with comedian Marc Maron on his “WTF Podcast,” Rannazzisi gave a detailed personal account of what happened. Rannazzisi said he worked as an account manager for Merrill Lynch and he was explaining his role in the company when Maron interjected.

[WTF is the president doing on a podcast called ‘WTF’?]

“Party starter,” Maron said.

“Sort of the party-starter of Merrill Lynch, yeah, until our building got hit with a plane and the party ended right there,” Rannazzisi said. “I worked on the 54th floor of the second tower.”

“Get the f— out,” Maron exclaimed. “Did you evacuate that day?”

“Yeah, I was there, and then the first tower got hit and we were like, jostled all over the place and then the Port Authority came on the loud speaker and they were like, ‘Hey, uh, explosion in Tower One, um, things are being taken care of, everyone remain where you are. Stay calm. We’re figuring things out. And I was like, ‘well, I’m going to go check this thing out.’ So I went downstairs, walked outside, saw all of the pandemonium and then about five or six minutes later [Rannazzisi made a whoosh sound]: bang.”

“While you were standing right there?” Maron asked.

“While I was standing underneath a giant overpass right by uh–”

“And all your co-workers were upstairs?” Maron interrupted.

“Yeah,” Rannazzisi continued. “But I couldn’t tell exactly where it went in so I had no idea. So I called up to the office. It was pandemonium. They were like ‘we’re on our way down. We’re on our way down.’ And then I just started f—in’ bookin’ it.”

“Oh my god,” said Maron, audibly horrified.

“And I got to about West Broadway when I stopped, caught my breath, and watched the second tower fall. Our tower fell first. The second one that got hit was the first one to fall. The impact was lower so there was more weight on top, I think, is the way it was described to me.”

But that’s not what happened. Absolutely none of it was true. After being confronted with an account that suggested he was lying, Rannazzisi admitted Tuesday in a statement to the New York Times that he had in fact fabricated his oft-repeated tale.

Merrill Lynch did not have offices in either of the twin towers, and told the Times that according to its records, Rannazzisi never worked for the company. At the time of the attack, Rannazzisi was in midtown Manhattan.

He tweeted the full apology Tuesday morning:

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.

There were also inaccuracies in Rannazzisi’s account of what happened to the woman he was dating at the time, who he later married. Rannazzisi said his wife was scheduled to report for work as a temp in the south tower, but through serendipity, she didn’t make it. Rannazzisi’s publicist, Matthew Labov, told the Times she was actually supposed to report for work in the World Financial Center, which is a different building.

Rannazzisi has a new Comedy Central special, “Breaking Dad,” which is scheduled to air on the network on Sept. 19.

“We just learned about this last night,” Comedy Central spokesman Steve Albani said in an email to the Post. “We are very disappointed to hear about Steve’s misrepresentations and are currently determining how we will move forward.”

Rannazzisi is also an actor on “The League,” an FXX show that’s currently in its seventh and final season. FXX is still proceeding with its plan to air the new season’s second episode tonight. It has completed production on 11 of the last 13 shows and expects to wrap in mid-October. Rannazzisi’s personal Web site has been taken offline.

“We are disappointed to learn that Steve Rannazzisi lied about being in the World Trade Center on 9/11,” FX communications vice president John Solberg said in an email statement to the Post. “It is upsetting that he would fabricate a story about having survived that horrible tragedy. It is also unfortunate that he did not admit to the truth sooner. That said we believe Steve is sincere in his apology and will do everything he can to make amends moving forward.”

An already-awful situation worsened when an under-informed Rannazzisi responded to a sarcastic tweet from “Saturday Night Live” actor Pete Davidson. Davidson’s father was a firefighter who died on Sept. 11, and he publicly castigated Rannazzisi for his mendacity, a point that was lost on Rannazzisi.

“It’s ok @SteveRannazzisi people make mistakes … Can’t wait to meet my dad for lunch later,” Davidson wrote.

Rannazzisi wrote back in a tweet he has since deleted, “thank you pete. i really appreciate it.”

To which Davidson, 21, replied, “I think you missed the point …”

Davidson later seemed to soften his stance, but in actuality, his sarcasm simply wasn’t as readily detectable. “All kidding aside this @SteveRannazzisi story sucks because he’s actually a funny comic and I love The League. It’s f—ed up,” Davidson wrote. “Take it easy on @SteveRannazzisi … He reached out to me and is truly sorry. We all sometimes lie and exaggerate a story to seem cooler …”

Davidson recently paid tribute to his father on Instagram. “Can’t believe it’s been 14 years. Over 2/3 of my life without you. It feels like it was just yesterday,” he wrote in the caption of a photo of them he shared Friday. “There’s not a day that goes by where I don’t think of you. You’re my hero. Can’t wait to see you again someday RIP dad 1/4/68-9/11/01 #neverforget.”

Davidson, who counted himself among Rannazzisi’s fans, elaborated in a Tuesday interview on the SiriusXM satellite radio show “Opie and Jim Norton.” He said he tweeted Rannazzisi “two or three” years ago. “I tweeted him saying, ‘Hey, I heard you got into comedy because of 9/11. I think that’s really cool,'” Davidson said. “And then he tweeted me back, ‘Something like that.’ And I was always like, ‘What? What a weird response.'”

Later in the show, Davidson was less forgiving. “He’s not sorry,” Davidson said. “He’s sorry he got caught.”

A few moments later, Elijah Wood, also a guest on the show, remarked on the Anger Industrial Complex that fuels so much conversation on the modern Internet. “That’s a little unfair,” he said. “Even if someone’s done something heinous, it can get to the point where it becomes harmful to their life based on just one stupid mistake because people just start to shame them. It makes me uncomfortable.”

“Yeah,” Davidson said. “But this is one of those where it’s, like, ‘f— you, dude.'”

This post has been updated.