Former site of the St. Francis Dam

The St. Francis Dam was a concrete gravity-arch dam, designed to create a reservoir as a storage point of the Los Angeles Aqueduct. The dam was located 40 miles (64 km) northwest of Los Angeles, California, near the present city of Santa Clarita. The dam was built between 1924 and 1926 under the supervision of William Mulholland, chief engineer and general manager of the Los Angeles Department of Water and Power (then called the Bureau of Water Works and Supply). Three minutes before midnight on March 12, 1928, the dam catastrophically failed, and the resulting flood killed more than 600 people. The collapse of the St. Francis Dam is 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, and it marked the end of Mulholland's career.