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Government or official record

History of California Dam Safety

California Department of Water Resources

Cross-File evidence ledger

Where this source supports the record

Each entry separates the File’s editorial relevance note from its exact, section-level claims. A bibliography link without a direct claim is labeled plainly.

  1. Engineering failures · 12–13 March 1928

    The St. Francis Dam Disaster

    St. Francis Dam ruins in San Francisquito Canyon · United States

    Open File evidence →
    Why editors use it here

    State account of the failure, flood corridor, losses, official cause finding, and creation of dam-safety regulation.

    1. Quick read

      Minutes before midnight on 12 March 1928, the two-year-old St.

      Reviewed 24 July 2026
    2. Trigger and conditions

      The dam catastrophically broke apart at about 11:57 p.m.

      Reviewed 24 July 2026
    3. Uncertainty

      Death estimates range from the 385 known in 1928 to more than 450; USGS gives at least 431, while California's dam-safety history uses more than 450.

      Reviewed 24 July 2026
    4. Why it matters

      The disaster was not simply a concrete wall breaking.

      Reviewed 24 July 2026