At 10:30 AM He Said Safe — By Midnight 400 Were Dead

The St. Francis Dam disaster killed over 400 people hours after William Mulholland declared it safe. On March 12, 1928, his 205-foot dam holding 12.4 billion gallons in San Francisquito Canyon was pronounced sound at 10:30 a.m. and collapsed at 11:57 p.m., sending a 140-foot flood 54 miles to the Pacific. The documentary traces the 20-foot height increase without widening the base, the muddy leak and ancient landslide the inspection missed, and how the catastrophe created California's first dam safety laws.