The deadliest storm on record

The Bhola cyclone pushed a wall of water across the low islands of the Ganges delta at night, at high tide, on a full moon, and killed somewhere between three and five hundred thousand people.

The islands are barely above sea level and the funnel shape of the Bay of Bengal concentrates a surge like a megaphone. The relief effort was so badly handled that it fed directly into the war that made Bangladesh a country a year later — a storm surge with a national border as a consequence.