Hurricane in the Atlantic, typhoon in the Pacific, cyclone in the Indian Ocean and Bay of Bengal — the physics is the same, but the geography is not. The Bay of Bengal is shallow and funnel-shaped; the delta at its head is flat, densely populated, and barely above sea level. Storm surge has nowhere to go but across the land. The result is a record of catastrophic mass death: the 1970 Bhola cyclone killed between 300,000 and 500,000 people. The human story of South Asian cyclones is one of recurring disaster followed, in recent decades, by a genuine and hard-won survival revolution.
The 1970 Bhola cyclone struck East Pakistan in November of that year and killed somewhere between 300,000 and 500,000 people — the estimates vary widely, and no one will ever know the true toll. It remains, by any count, the deadliest tropical cyclone ever recorded. The storm's toll cannot be explained by its winds alone. What made it catastrophic was where it landed: on a flat river delta barely above sea level, so crowded with people that evacuation was nearly impossible, and governed by an authority so far away that its slow, widely condemned relief arrived too late to save the living. The anger that followed helped spark the liberation war that created Bangladesh. A storm did not start a revolution. But a storm, and the failure it exposed, helped break a country in two.