Kowalski goes into a crowded bar for a few drinks after work. A couple of hours later, he feels the need to take a shit, so he asks the bartender for directions to the toilet.
"It's upstairs," replies the barman, "down the hall, turn left, and second door on the right."
Kowalski, who is pretty well plastered by now, blinks at the bartender, and sets off in search of the toilet.
He manages to get up the stairs all right, but gets confused from there onwards. Finally, completely lost and desperate to relieve himself, he pulls up a loose board from the floor and makes his deposit. But what Kowalski does not know is that this floorboard is right in the middle of the ceiling of the bar below.
When he gets back downstairs, he finds that the bar is completely deserted. The place smells awful. Kowalski goes over to the bartender, sits down at the bar and orders another drink.
"Where did everybody go?" asks Kowalski, drunkenly.
"My God!" replies the bartender. "Where were you when the shit hit the fan?"
