I was changing a hydraulic motor on a conveyor one night in a paper mill when the power went out due to a storm. the first thing I heard over all of the equipment slowly cycling down was the Plant Foreman yelling at the top of his lungs EVRYONE FREEZSE IN PLACE NOBODY MOVE A MUSCLE. I thought that was sound advice, even though anything powered by hydraulics would have stopped almost the instant the pumps stopped supplying pressure not everything is run by hydraulics there must have been 100s of electric motors many not having auto braking electromagnetic release, plus the rotating kinetic energy in just one of those 5000lb rolls of paper is enough to do some serious damage. There was not a lot of battery backup powered emergency lighting either just mainly at the exit doors and some along the main escape pathway in case of a fire, those switched on instantly but added very little illumination to the couple hundred thousand sq ft plant