Anyone who watches It's Always Sunny in Philadelphia on a regular basis knows that Danny DeVito's Frank Reynolds has gone through some hard knocks. And every season, the gang almost does him in with their shenanigans. The show's unprecedented Season 11 just launched a few weeks back. And as star Charlie Day tells it, it was almost the last for poor Danny DeVito.

Danny DeVito is in his early 70s, but that doesn't stop him from participating in the outlandish behavior that a show like It's Always Sunny in Philadelphia requires. He is usually game to participate in whatever stunt the gang asks of him. But one of these incidents got a little out of hand, and the legendary sitcom and movie actor almost drowned. Charlie Day recounted the harrowing moments on set to Conan O'Brien earlier this week. Here's what happened.

"We did an underwater sequence, and Danny's incredibly buoyant-like a bouey. 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. 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. And that look of panic in his eyes like, 'This is the end, these guys killed me.'

Of course, an on set of emergency scuba divers dove into rescue poor Danny DeVito. But the scene left him shaken up. The actor recovered from this mishap quickly, but he didn't want to look at the rest of the cast for that shooting day and quickly left the set. Explains Charlie Day.

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

It's Always Sunny in Philadelphia Season 11 is only four episodes into this new season. And it's already taken quite a toll on poor Frank. In the second episode, Danny DeVito's character took a long fall out a window that bashed in his head. And there will be more danger in Frank's life as this season continues. An all-new episode airs tonight on FXX at 10 p.m. ET. It finds Mac and Dennis moving to the Suburbs. Luckily, Danny DeVito lives to see another day. It's Always Sunny in Philadelphia just wouldn't be the same without him.