The storm surge from the 1991 cyclone was particularly catastrophic because there was a combination of a 240 km/hr wind speed, low pressure, and especially a high tide. The 6 meter surge coupled with these conditions to destroy vast amounts of land and cause many deaths. Due to the low elevation in many parts of Bangladesh, the storm surge was able to travel very far inland and cause much greater damage. A similar type of storm surge known as a tidal bore also compounded the damage. This wave is usually experienced in a narrow river or estuary and is caused by the rushing of water that advances upstream like a wall of water. This tidal bore was observed in the Meghna estuary and other southern coastal areas.