The Johnstown Flood, otherwise known as the Great Flood of 1889, was a major flood that happened in a city called Johnstown, Pennsylvania, in the eastern United States. It was on a river called the "Little Conemaugh River". It was caused by the collapse of a dam called the "South Fork Dam", upstream, after several days of heavy rain. The date it happened was May 31, 1889. 2,209 people were killed by the 20 million tons of water that flooded the town. The flood also resulted in $17 million in damages. 