The Great Flood of 1889, widely considered to be one of the worst natural disasters in U.S. history, engulfed the town of Johnstown, Pa., after the catastrophic failure of the South Fork Dam following several days of heavy rainfall. As much as 20 million tons of water was estimated to have been released upon the town, killing about 2,200 people.
Despite the devastation, the disaster prompted the transformation of one of America's most heralded disaster relief organizations, the American Red Cross. The Johnstown flood was the first peacetime disaster relief effort handled by the organization.
Since it also succumbed to devastating floods in 1936 and 1977, Johnstown's persistence is especially inspiring. Today the city remains the proud home to more than 20,000 residents, according to the 2010 census.