Viggo Mortensen — The Lord of the Rings: The Two Towers
“The Lord of the Rings” had a lot going on. From the costume and set designs to the epic story-telling, organizing it was a massive undertaking. And with that amount of stress, sometimes you can lose track of “smaller” details, like your actor’s whereabouts.
In one scene, Viggo Mortensen’s character got shot in the back with an arrow meaning that the actor had to lie face down in a river. Unfortunately, the rover’s current was a little stronger than everyone anticipated. With his heavy costume, the actor almost drowned.
George Clooney — Syriana
Little known tidbit: George Clooney almost died on the set of Syriana. The mega-star broke his back during an incident that happened on set. The actor feared that he may never walk again and spiraled into an extremely dark place.
During his time in the hospital, there was actually more than one occasion where the actor even thought of calling it quits altogether. Thankfully, in the end, he recovered.
Isla Fisher — Now You See Me
In the film "Now You See Me"Isla Fisher experienced a horrifying time while being trapped underwater. The scene dictated that she pretends to struggle to get free herself by her shackles in the water enclosure. Naturally, the struggles just look like really good acting and the actress was actually in trouble.
Her chains got stuck so she couldn't actually swim to free herself. The crew watching thought that she was just really convincing. Luckily the actress managed to pull the latch and set herself free.
Jason Statham — The Expendables 3
In 2013, tough British actor Jason Statham accidentally drove a semi-truck in the Black Sea. The actor got into this horrible accident on set and revealed the story on "The Tonight Show With Jay Leno."
According to the actor, while driving the truck in Vrana Bulgaria, he was supposed to stop the strike but something malfunctioned and he ended up pummeling into the water.
Michael J. Fox — Back to the Future III
Michael J. Fox was no stranger to playing the "Back to the Future" character Marty McFly. Unfortunately, things didn't go as smoothly as the first two times and Fox ended up getting almost very, very badly injured. In the scene where Fox gets a noose around his neck in the town square, things went a little awry.
Director Robert Zemeckis wanted to make eh scene look more realistic and unfortunately in the third take, the actor was actually getting hanged. Fox swang unconscious at the end of the rope for a few seconds before the director had realized what he had done.