The Comedy Central celebrity roasts have featured their fair share of offensive jokes over the years, but perhaps none were more legendary than the ones Gilbert Gottfried told at the 2001 roast of Hugh Hefner. Just a couple of weeks after 9/11, Gottfried got up onstage at the Friars Club in New York City and decided to address what was on everybody’s mind. “I have to catch a flight to California,” the comedian began. “I can’t get a direct flight. They said they have to stop at the Empire State Building first.” The crowd quickly turned on Gottfried, hissing and booing, with one person yelling out, “Too soon!”—which Gottfried took to mean that he didn’t pause long enough between the setup and punchline.

Amazingly, Gottfried was able to win the audience back by launching into one of the filthiest bits ever performed at the Friars Club. His rendition of the classic “Aristocrats” joke, complete with vulgar descriptions of incest and bestiality, is something that comics continue to marvel at to this day. In that moment, Gottfried figured he couldn’t lose the crowd any more than he already had and peppered his closer with the most offensive material he could think of, much to their delight. You can check out portions of the bit courtesy of the 2005 documentary The Aristocrats below.

A Fight Over One Infamous Joke Kept Jeff Ross Off the Roast Stage for Years

By the time Gottfried’s set made it on the air, it was heavily edited and didn’t include his infamous 9/11 joke. One person who fought for its inclusion behind the scenes was the self-proclaimed Roastmaster General Jeff Ross, who also served as a producer of Hefner’s roast. According to Ross, he’d gotten into a disagreement with another producer about whether or not the 9/11 material should be used—Ross himself had made a joke that same night about Rob Schneider bombing, saying, “Hasn’t there been enough bombing in this city?” Ross insisted that the roast was a significant historical event that people would be looking back on for years to come, but the offending jokes were ultimately left out of the broadcast.

Ross’s pleas didn’t just fail to convince his fellow producer to give the jokes the all-clear; they ended up keeping him off the dais of the Comedy Central roasts for four years. It wasn’t until the Pamela Anderson roast in 2005 that he was finally invited back, and he wouldn’t produce one of the shows again until Charlie Sheen’s 2011 roast. Gottfried, on the other hand, was asked back the following year for the Chevy Chase roast, which he was completely edited out of. He’d go on to appear in seven more roasts for the network, taking memorable shots at everyone from Bob Saget to Roseanne Barr to Donald Trump.