I'm actually surprised I didn't write about this, but I can't find it, so I must not have.
Back in 2000, when I worked for Negiyo on third shift, the power goes out and the backup generator kicks in. That's all fine and good, but the fact that the power went out caused all the sysadmins to scury around trying to figure out what caused the power outage. The weather wasn't bad and as far as anyone knew, FPL (Florida Power and Light) [1] wasn't having any problems in the area.
Turns out that it was a planned outage to test the backup generators. The management company of the property had sent notice to Negiyo about the planned outage, but the secretary who received the notification promptly discarded it, forgot about it, or lost it, so no one else in Negiyo had a clue.
It was an amusing night.