The underground tree squirrel blackout
Never saw a colleague pull a "Fred's Head," but once, with all the staffing happily doing staff things, the building suddenly went dark. The UPS started to scream and the server shut down, though by then all the other work stations were already dark. The lights were out and the phone system dead. The boss had us checking the breakers to the building, but they were fine. The city utility said, "it wasn't us!!" An electrician was called in and found that we had power to the pole and down the descender to where it entered a conduit under the drive way into the parking lot. At the riser though, where the line entered the building, there was no power. The enter undergroun line had to be exposed and the conduit dismantled before the "cultprit" - a tree squirrel - who had for some squirrelly reason mades it way into the conduit and half way to the far end before settling in to chew through the power line with fatal results.