Three minutes before midnight on March 12, 1928 the St. Francis Dam collapsed, sending over 12 billion gallons of water and debris rushing down the Santa Clara River Valley from San Francisquito Canyon to the Pacific Ocean, 54 miles away. In five and a half hours more than 400 peoples lives were claimed as they were swept away in the dark and murky waters. It is considered to have been one of the worst American civil engineering disasters of the 20th century and the third-greatest loss of life in California history.