Another instance where danger was a very prominent issue in film was the making of "Noah's Ark" in 1928. Durring the climactic flood scene of the story of Noah's Ark, several extras were asked to swim around in a pool while they dumped water into it. I remember vaguely an interview with Delores Costello (on of the main actresses for the film). She stated that people would get up out of the water because they were drowning and the director told them to keep swimming, that the show must go on. Three people died durring that scene and countless others injured from props and set dressing falling on them and being pushed around by the water being dumped on them. She recalled an extra hanging on to the door of her wardrobe room. She could see that he was badly hurt and that he needed medical attention. She asked if he was alright, he said it was alright, but he thinks someone may have died. The clip above is that very scene. It's awful to watch knowing that the director Michael Curtiz made the choice to keep those people in the water. This film and many other films that had unfortunate accidents encouraged the laws to be changed and other safety rules put into effect.
I watched a documentary on Netflix once about the making of the Texas Chainsaw Massacre film in 1974. The events of the film were much more horrifying than the story of the film itself. The film is available on Netflix still I believe. I would recommend watching it and absorbing it as a 'How not to make a film' film. It's incredible that no one died durring the making of it. As an independent film they never had faith in it but eventually it made it very big and it became one of the biggest horror fliks ever.
If you have time I would consider watching it. I have actually found it on youtube. Although, I'm not sure it is the entire documentary.
As a director I always keep this in mind. I try to put myself in my actors shoes and wonder. How would I feel if a director asked me to do that. What am I putting my actors through, is there any other option we could do in order to get the same effect without putting anyone in danger.