"As a young man, I made a mistake that I deeply regret and for which apologies may still not be enough," he wrote on Facebook. "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," he continued. "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," said Rannazzisi. "It only made me more ashamed. How could I tell my children to be honest when I hadn't come clean about this?"
Rannazzisi concluded his statement: "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."
Rannazzisi's past accounts state that he was working at Merrill Lynch in the south tower when the first plane struck, and fled minutes before the second plane hit. He attributed this experience with inspiring his move to Los Angeles to pursue comedy.
A video on YouTube shows a 2009 interview on Marc Maron's WTF Podcast, where Rannazzisi told his false story of his 9/11 experience. The conversation starts around 25 minutes in.
One person who has come to Rannazzisi's defense is SNL cast member, Pete Davidson, whose father died in the September 11 attacks, when Davidson was only seven years old. The comedian tweeted, "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."
"Unfortunately this is a very touchy topic and very near and dear to people's hearts. It's years later but he apologized and owned up to it like a man," Davidson wrote in a followup tweet.
..Unfortunately this is a very touchy topic n very near n dear 2 peoples hearts.Its years later but he apologized n owned up 2 it like a man
It's a softer tone than Davidson took on the Sirius XM radio show "Opie and Jim Norton" this morning, when they discussing Rannazzisi's admission.
"He’s not sorry. He’s sorry he got caught," said Davidson. He then agreed with actor Elijah Wood -- who was also a guest -- about how the Internet can sometimes develop a mob mentality around people who make mistakes, before remarking, "But this is one of those where it’s, like, 'Fuck you, Dude.'"
Following Rannazzisi's apology, FX Networks released a statement to ET.
"We are disappointed to learn that Steve Rannazzisi lied about being in the World Trade Center on 9/11. It is upsetting that he would fabricate a story about having survived that horrible tragedy," the network wrote. "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."
Rannazzisi is not the only celebrity who has caused controversy as the nation remembers the horrifying September 11 attacks. Entourage actor Adrian Grenier caused outrage after an Instagram post he made about the attacks.