On March 7, 1928, the St. Francis Dam, located 80 km from Los Angeles, collapsed, sending 12.4 billion gallons of water rushing through San Francisquito Canyon. The disaster, one of the worst engineering failures in U.S. history, resulted in at least 431 deaths, with some victims found as far as the Mexican border decades later.

The dam, supplying water from Owens Valley to meet Los Angeles’s growing needs, had shown cracks and leaks since 1926. However, chief engineer William Mulholland dismissed concerns, insisting it was stable. On the morning before the collapse, Mulholland’s team inspected the dam and deemed it safe but needing future repairs. Hours later, it failed catastrophically. Investigations attributed the collapse to defective foundations.

The disaster was a major event in the California Water Wars, a long-standing battle between farmers, ranchers, and city officials over water rights. Nearly a century later, California still struggles with water shortages. During wildfires in January 2025, low hydrant pressure hindered firefighting efforts, with officials blaming high demand while Donald Trump accused state policies of overregulation. The state’s water crisis remains a pressing issue.