On the night of April 29, 1991 a powerful cyclone came out of the Bay of Bengal and struck the Chittagong district of Bangladesh, causing nearly 139,000 deaths.
The system originated in the southern Bay of Bengal on April 24. It meandered slowly westward for several days before being picked up by an advancing trough on April 27th which caused it to accelerate northward and gain strength. At its peak before landfall, the maximum sustained wind speed was estimated at 160 mph (260 km/hr). The storm drove a surge of sea water of 20 feet (6 meters) over the flat terrain of the Chittagong district and caused US$1.7 billion in damage as well as the high casualty level. Nearly 2 million people evacuated the vulnerable area prior to the cyclone, but some did not, either because they received short notice or because they did not believe the forecast strength of the storm.