Putting on a live show in a pandemic can be seriously tricky.

On Thursday, Kenan Thompson appeared on “The Tonight Show”, and host Jimmy Fallon asked him about the experience of doing a downsized Christmas episode of Global’s “Saturday Night Live” last month due to the COVID surge.

“That was an almost catastrophe,” Thompson remarked. “It slammed into the wall.”

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Paul Rudd was set to host final episode of 2021, with Tom Hanks and Tina Fey making special appearances, but at the very last minute, most of the cast and crew were sent home.

“That’s just five people, when it should be 60,” Thompson said, looking as a photo of himself, Rudd, Hanks, Fey and Michael Che from that night.

“He’ll get his get-back, though,” he added of Rudd.

Explaining how that week went, Thompson said, “We were working like it was a regular week on the show.”

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But things started to take a turn as COVID case numbers began to surge in New York due to the Omicron variant.

“The numbers were just going crazy in New York, and then by Saturday, the NBC just called it,” he said.

Despite it all, the comedian added, “The show must go on.”

He explained that while they weren’t able to do a normal show, they had luckily already filmed some pre-taped sketches, and the rest of the episode was largely done as a clip show.

“Saturday Night Live” airs Saturdays at 11:30 p.m. ET, 8:30 p.m. PT on Global.