Flood in the Desert tells the dramatic story of the March 1928 collapse of the St. Francis Dam and its aftermath, which was the second deadliest disaster in California history. The resulting flood killed over 400 people, destroyed millions of dollars of property, and washed away the reputation of one of the most celebrated men in Southern California, William Mulholland. A self-taught engineer, Mulholland had ensured Los Angeles' remarkable growth by building a cement aqueduct that piped water from the Owens Valley across the Mojave Desert and into the arid city, 233 miles away. He had good intentions, but the bursting of his St. Francis Dam, the city's largest single reservoir, was a colossal engineering and human failure.—PBS