It’s an unprecedented yet largely forgotten nightmare in California, one to this day is the largest man-made disaster in terms of human life.
The collapse of a dam created a massive wall of water killing hundreds of people, with most of the deaths in Ventura County. The reason it’s mostly overlooked today is that it happened 89 years ago.
The St. Francis Dam was built in San Francisquito Canyon, near what is now Santa Clarita. It was designed by William Mulholland, the man who created the state’s legendary aqueduct which brought water from the Owens Valley to Southern California, making the region’s growth possible.
On March 12th, 1928 the dam was full. The on-site supervisor became concerned because he was seeing brown water, which could be a sign of a leak. The dam had a series of small leaks as it was being filled, but they were considered to be normal as part of a cement filled dam. The supervisor called Mulholland, who came and inspected the dam, and left, apparently feeling there wasn’t a major issue. Some 12 hours later, the dam collapsed.
The dam break sent a 140 foot high wave of water from northwestern Los Angeles County down the Santa Clara River bed, hitting communities along its banks in Ventura County.
Historian and author Jon Wilkman has written a book about the St. Francis Dam disaster. Wilkman spent more than 20 years researching the accident, leading to the book “Floodpath: The Deadliest Man-Made Disaster of 20th Century America, and the Making Of Modern Los Angeles.”
At 11:57 p.m. on March 12h, the dam collapsed. Wilkman says because of the hour, most people in the path of the flood were home asleep. It took about 90 minutes for the wall of water to work its way to Fillmore, and then Santa Paula. More than 450 people died. The exact number isn’t known, because some bodies were buried under several feet of debris, and other bodies were swept all the way out to the ocean.
The disaster ended Mulholland’s career. He was devastated by what had happened, and died seven years later. Wilkman says it combination of engineering problems and the placement of the dam in an area with difficult geological conditions which contributed to the disaster.
The start of the Depression in 1929 sidetracked interest in the accident, and no one wanted to try to build a new dam in the same area. But, some good came out of the disaster. The collapse led to California adopting some of the toughest dam safety requirements in the nation. However, there is a modern day issue. Many of the dams in the state, and nation are decades old, and studies have shown a large percentage of them have major maintenance issues. Wilkman cites the recent near disaster in Oroville as an example.
While the St. Francis accident has been largely forgotten, it may get new attention. Wilkman’s book about the disaster, which has been an “Amazon” best-seller, has been optioned by a producer for development as a mini-series.