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How Jenna Fischer once saved the lives of her ‘Office’ castmates while filming

An episode of the classic sitcom titled “Work Bus” earned the nickname “Death Bus” after this incident. 
Jenna Fischer as Pam Halpert The Office
Jenna Fischer as Pam Halpert in "Work Bus," the Season Nine episode that packed plenty of unscripted drama for the sitcom's cast. Chris Haston / NBC

A popular episode from the final season of “The Office” could have become the final episode of anything ever for the beloved sitcom’s cast — if it hadn’t been for quick-thinking star Jenna Fischer.

Bryan Cranston, who served as director on the “Work Bus” episode, recently visited “The Late Show” and explained to host Stephen Colbert why the experience came to be known as “Death Bus.”

“That’s just so unfair,” Cranston dryly joked about the nickname cast members gave the ep.

But “Work Bus,” which was meant to lampoon the dangers of working at Dunder Mifflin under Dwight (Rainn Wilson), earned its morbid moniker because of the danger the cast encountered while filming it.

“We have to go onto a bus, and we set up desks on the bus to be able to continue to do the work," the 66-year-old explained. "In order to do that, we have all these actors in there, they pulled on a trailer ... an AC system."

But there was a little logistical problem.

"What they didn’t plan on (was) where the intake for the refrigeration system was was exactly lined up to where the tailpipe of the bus was," Cranston continued. "So the exhaust of the bus was going right to the intake, cooling it — because when you breathe in carbon monoxide, you want it cool. The cooler, the better. ... As you fall into a deep coma and eventually die, you want to know that you went out smoothly, softly, comfortably."

While it's amusing in retrospect, thankfully, one member of the cast took the situation seriously from the start.

John Krasinski as Jim Halpert, Rainn Wilson as Dwight Schrute
John Krasinski as Jim Halpert and Rainn Wilson as Dwight Schrute in "Work Bus."NBC

"Jenna Fischer actually saved everyone’s life," he said of the actor who played Pam. "She said, ‘I smell exhaust. It’s coming inside the bus.’ And I’m like, ‘Jenna, c’mon. ... How is that possible? It’s not possible.'"

However, when he stood up on a chair and had a sniff, he discovered just how possible it was.

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"I stuck my nose up in there, and sure enough, it was billowing down," Cranston revealed, before adding, "I realized, 'Oh, my God.' We could have all been dead."

And though he joked that it would have made for "one hell of a" series finale, he still insists it's unfair to call the episode "Death Bus" given the bright side of the story — "no one died."

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