A data center where I work had a naked big red switch without a protection plate. Until I flagged up this lack and let the IT people know about it, it was a disaster waiting to happen.
Similar situation here. A big red button on the wall in the basement data center - nobody knew what it was for and were afraid to turn it off. One day a night operator decided he was going to flip the switch and see what happened. It cut power to the entire datacenter, including the elevator systems. We spent a few days getting all the systems back online.
Had another instance where a pipe ran from the floor above right over the UPS. Construction workers on the first floor decided to poor some unusued paint into it (figured it was a drain pipe) and of course, we lost power again.
There's a plate on the switch now, praise Eris.