St. Francis Dam
Construction on the 600-foot-long, 185-foot-high St. Francis Dam started in August 1924. With a 12.5 billion-gallon capacity, the reservoir began to fill with water on March 1, 1926. The dam was designed and built between 1924 and 1926 by the Los Angeles Department of Water and Power, then named the Bureau of Water Works and Supply. The department was under the supervision of the city’s chief engineer William Mulholland. At two and a half minutes before midnight on March 12, 1928 the dam failed catastrophically sending a 180-foot-high wall of water crashing down San Francisquito Canyon. The resulting flood killed up to 600 people. The collapse of the St. Francis Dam is considered to be one of the worst American civil engineering failures of the 20th century and remains the second-greatest loss of life in California’s history, after the 1906 San Francisco Earthquake and fire. The disaster marked the end of Mulholland’s career and a significant moment in Southern California history.