Last night my six-year-old Hoover dishwasher failed catastrophically, flooding the kitchen. Everyone had gone to bed, but fortunately my son came downstairs to get something and found it awash. Even though it hadn't been left running, water was flowing in the inlet and out the bottom.
I turned off the water tap and switched the power off at the mains, and we mopped it all up from the floor before going back to bed. This morning the floor had dried off but the bottom of the machine was still full of water.
Strangely, the user manual says there are two separate anti-flooding mechanisms; one on the inlet hose just next to the mains tap, and one internal one, presumably a float-based switch to activate the drain pump. Neither did a damn thing.