While performing his play “The Second Greatest Entertainer In The World”, Dick Shawn collapsed onstage, as planned, leading into intermission. He did this at evey performance, and always remained onstage in his collapsed position. During his final performance, everything seemed normal, until the 2nd act began, when he did not spring up. He died after the collapse.

On film, Brandon Lee’s character in The Crow is shot dead. During the filming of that scene, a misloaded gun firing a “blank” killed him.

Here is Keanu Reeves training for his John Wick role:
https://www.youtube.com/watch?v=ueZPB3ld5os
https://www.youtube.com/watch?v=rCIgpUTvfsA

Didn’t some tv series character from years ago actually give birth in one episode?

Daniel Day Lewis in My Left Foot.
He remained in his wheelchair throughout filming, even when cameras weren’t rolling, suffering two broken ribs in the process.

Christian Bale’s staggering weight loss, on his own initiative, from The Machinist, deserves mention.

When Gwyneth Paltrow was making Shallow Hal she used the “fat suit” she had to wear for filming out into public. She was astounded at how people treated her.

Leonardo DiCaprio prepared for his role in The Revenant by sleeping in dead animal carcasses. I think doing something as extreme as that definitely helped his character have a real sense of anxiety and determination to want to survive his surroundings

Steve Carrell got waxed on camera. “Kelly Clarkson!”

Tom Hanks lost tons of weight for his role in Cast Away. He gained it back. He credits that for the diabetes he has now.