That was a close call!

Ed Harris almost drowned after he ran out of air. James Cameron kept rolling. As soon Harris came out, he punched Cameron in the face.

Ron Perlman hit his head and almost drowned while filming a water scene. Winona Ryder almost drowned as well.

While filming the shot of Griff's gang crashing into the courthouse, a stuntwoman was accidentally propelled into a hard stone pillar, rather than the breakable glass they were supposed to hit and nearly died. This was the take that was used, and you can see her hit it in the final cut.

During the hanging scene, the catch that would prevent Michael J. Fox from hanging failed, and the crew didn't notice until filming stopped. They immidiately cut him down and he passed out.

For a scene that took place at an amusement park, they filmed a scene on a roller coaster, but one of the actors thought the camera mounted on the coaster looked unstable so they did a test run. It flew forward and would've killed all the actors had they been on the coaster at the time.

While filming a scene that required her character to have a heart attack Natalie Wood had a real heart attack, and the crew didn't notice until after the take was finished.

A sudden gust of wind blew a top off the top of an RV that was being held down by a boulder, and it landed where Aaron Paul had been standing only a few seconds ago.

The child-catchers vehicle got in a bad wreck that could've been fatal had the actor not jumped out of the vehicle as quickly as he did.

During the scene where Alex is being drowned, the breathing machine malfunctioned, so Malcolm McDowell was really being drowned in that scene. Nobody noticed until after the take was over.

The woman that was being pulled onto the train by Yuri, and almost had her legs mangled by the train when she tripped.

Emily Blunt almost killed Tom Cruise when she was filming a car chase by driving into a tree.

The make-up John Hurt had to wear was extremely heavy. As a result, one day when he decided to take a nap, he almost suffocated to death.

While filming a car chase sequence, the brakes on Jason Statham's car failed, and he drove directly into the sea. He managed to escape from the sinking car, and swam up to the surface.

Sean Connery saved Daniela Bianchi's life when a helicopter was coming in too steep and was headed straight for her, but he tackled her out of the way.

During the filming of the episode with a lion, Bob Denver (Gilligan) was almost mauled to the death by the lion after it took a swipe at him while filming a scene.

Had Eli Wallach lifted his head even an inch during the train scene, he would've been decapitated.

While on set, Kristen Chenoweth was hit in the face with a light fixture that had fallen. The hit resulted in a concussion, skull fracture, and broken nose.

The fire at the movie theater was real, and it got so out of control that Eli Roth (who passed out from the intense heat) and Omar Doom almost burned to death.

While filming the first battle in the woods, the animatronic horse Tom Cruise was riding on malfunctioned, and he was nearly decapitated by a sword swing from Hiroyuki Sanada, but he was able to stop the blade from cutting off the head inches from his neck.

Johnny Depp fell off his horse while filming a scene and was nearly trampled.

A stuntman accidentally threw a knife straight at Viggo Mortensen while filming the battle Uruk-Hai, but he was able to deflect it with his sword.

Viggo Mortensen was pulled by a river current and almost drowned during the filming of the river scene.

While filming the series finale, Matthew Fox was stabbed in the chest with a knife when it wasn't swapped with a collapsable knife. Fortunately he was wearing a Kevlar suit that saved his life, which he almost didn't put on.

Lucille Ball almost drowned in a shower that was completely filled with water. Vivian Vance saved her by literally pulling her up by her hair.

Hilary Swank got a really bad staff infection on her foot during her boxing training, but ignored it. Finally it ruptured, forcing her to go to the hospital. The infection was so bad by the time it was treated that it nearly reached her heart.

Brandan Frasier was almost hanged to death when the catch failed (much like BTTF 3 example).

The kid who played Atreyu almost drowned in the mud during the filming of the Swamp of Sadness when his foot got stuck in the elevator that was supposed to lower him.

An empty van started to roll down a hill that would've killed Uma Thurman and someone else. Pierce Brosnan happened to see it, and unable to get either of them to hear him, raced and jumped into the van and was able to stop it before it reached them.

Oliver Robins was really being strangled by the toy clown and at first the crew didn't notice, but Spielberg finally realized it and rushed to his aid.

During the filming of one episode that required Craig Charles to walk backwards underwater, he nearly drowned.

Meryl Streep fell off the raft during the last take of the raft scene, and nearly drowned.

Jackie Chan's skull was almost crushed by two metal boxes slamming together that missed him by mere inches.

Arnold Schwarzenegger almost drowned on the set.

Shortly after filming a scene in a water tank, an electrical light fell and landed in the tank, which would've killed Mark Hamil had he been in it.

While filming the final climactic chase, Gunnar Hanson slipped and the chainsaw flew out of his hands and landed just inches from his face.

His mask also slipped during another take of the same chase, which blinded him temporarily, and he almost sawed Marilyn Burns in half.

During the filming of the dinner scene, the experience was so torturous, that Gunnar Hanson admitted that his mind had started to slip and he nearly murdered Marilyn Burns to get the scene over with.

Fred Haise (one of the Astronauts from Apollo 13) who was a stunt pilot in this film, got in a really bad BT 13 crash which burned two-thirds of his body and hospitalized him for 3 months.

Buddy Ebsen (the original choice to play the Tin-Man) had a bad allergic reaction to the make-up that ending up leaving him hospitalized.

Also, Margaret Hamilton suffered severe burns during one of the scenes that involved the pillar of smoke the witch would disappear and reappear in.