Sometimes just measuring isn't enough...
Not exactly a fail like some of the others here, but still IT...
I once asked a building contractor to cut a hole in a comms room floor tile, as there was an additional rack going in the next day. He marked it out and was about to drill a corner hole when I asked if it wouldn't be better to take the tile out. He opened the last cab in the line, put his arm through the hole under it, and proceeded to have a grope around. "Nope, there's nothing under that tile". After several further failed (increasingly heated) attempts at trying to convince him to take the tile out, he said I should stick to IT and he didn't have time to discuss it and drilled the hole.
Nothing bad happened, but before he got his jigsaw blade through the hole, I tried again. He again had a feel under the tile through the other cabinet... "Nope, no need to take the tile out". He got about half way around the hole with the jigsaw before there was a loud bang, a bright flash, and the comms room (and an awful lot of the building) went very quiet... followed by the office manager knocking on the door... followed by the contractor's boss... followed by the electrical contractor... the supply cable he'd cut through was just out of his reach under the tile.
Murphy's law in action.
Biting the hand that feeds IT
