How Danny DeVito almost died while shooting the new season of 'It's Always Sunny in Philadelphia'

Danny DeVito is used to doing some crazy stunts on the set of "It's Always Sunny in Philadelphia," the FXX comedy, but filming one particular scene for season 11 almost killed him.

During an appearance on "Conan" Tuesday night, Charlie Day explained how DeVito, 71, almost drowned. 

"We did an underwater sequence, and Danny's incredibly buoyant, like a buoy," he said. "It was hard to get him down, so we really had to weigh him down to get the shot where we're all holding hands."

The rest of the cast was able to swim up after the shot was over, but since DeVito was weighed down, he struggled to get up to the top. 

"And when the shot was over and we were all trying to get back to the surface for air, we all quickly got through the water but because we weighed him down, he sort of got halfway and was going nowhere," he said. "And that look of panic in his eyes of like, 'This is the end, these guys killed me.'"

Safety divers pulled him out, but DeVito was done for the day. 

"He went straight home," Day said. "He was like, 'Goodbye, that's the end of filming for today.' I don't blame him."

Luckily for "It's Always Sunny" fans, though, it wasn't DeVito's last day on set.

Watch the clip of Charlie Day explaining the incident from "Conan" below: