Hollywood Health and Safety

Continuing the discussion on Health and Safety practices in Hollywood movies (see Gere Change and Bottom Gere, below), someone (Simon, I believe?) comments: "Basic health and safety has long been overlooked by Hollywood with rare exceptions - such as the sublime moment in the otherwise execrable Alien 3 where one soon-to-be dead person explains to another the correct way of holding scissors."

I agree, and here's the thing: given the context of the situation, such a caution does indeed seem incongruous, even humorous. But imagine how bad you would feel if, having somehow escaped the relentless jet-black nemesis that is the Alien, you then go and have a silly accident with a pair of scissors? How futile would that be? You'd be gutted. Perhaps literally.

Can anyone think of other examples from movies where good health and safety procedure has been overlooked with tragic consequences? Or are there any cases where H&S standards have been successfully applied? Comments please.