I flooded a dormitory once, but I blame building maintenance for tricking me into it.

I wake up and head to the bathroom. Turn on the shower, nothing happens. Try the sink, still no water. No advance notice to the residents, but the water must have been shut off for some reason. I have a class to go to, so I turn everything “off”, get dressed, and leave. I’d forgotten that one of the sink knobs was threaded the opposite way from the standard convention, so that one was full on when the water was restored. Came back to the dorm after lunch and realized exactly what I’d done as soon as I entered the hallway and saw the maintenance man running his shop-vac outside my room. It overflowed the sink drain, and the bathroom floor drain, flowed through the dorm room, and was in the process of flooding the hallway.