Watch a Tokyo commuter drive through a flooded tunnel

Driving through floodwater is risky at the best of times. It can cause irreparable damage to your engine or, in a worst-case scenario, your car could be dragged away by undercurrents leaving your life in danger.

From a purely logical viewpoint, then, driving through a flooded tunnel takes a special kind of stupidity. Especially when the water's high enough to break over the bonnet – the engine's intake can't be far away from the water line.