US Chemical Safety Board puts out some nicely done videos showing some recreated industrial accidents and what caused them. This one is about a deadly welding accident on a large holding tank. I personally disregard a lot of the 'safety nanny' nonsense, but when it comes to industrial/commercial work you cannot be too careful. Check out some of their other videos too and stay safe you guys.
Hot Work: Hidden Hazards
Hot Work: Hidden Hazards