They called America the land of opportunity, and for William Mulholland it was everything they promised. Born in Belfast in 1855, he left home when he was 15 years old and sailed for New York. After working as a lumberjack and miner, he moved to Los Angeles, where he cleared ditches and studied engineering. Within a few years he was running the city's department of water and power.
As Los Angeles boomed, Mulholland warned that the city would need more water. The most promising source was the Owens River, 200 miles away. But ranchers in the Owens Valley had plans for their own irrigation project, and so began the "Owens Valley War".
By fair means and foul (Mulholland's shenanigans inspired the 1974 film Chinatown), the engineer and his grasping financial backers acquired enough land and water rights to block the Owens Valley project. It simply remained for him to bring the water to Los Angeles.
Over the next eight years an army of workers blasted a channel across the desert. The completion of the Los Angeles Aqueduct in 1913 was an engineering triumph. However, the Owens Valley farmers were unimpressed.
In 1924 they began a campaign of sabotage, dynamiting sections of the aqueduct and threatening Mulholland. But the engineer's trump card was constructing a dam across the San Francisquito Canyon that would trap enough water to safeguard the city's supply for two years.
Geologists tried to tell Mulholland that his chosen site was in a fault zone, and that the rocks to either side of his vast structure were weak.
But their warnings were ignored.
By March 5, 1928, the reservoir was full. And one week later it failed, unleashing a 75-foot-high wave that scoured a path to the sea two miles wide and 70 miles long. In Santa Paula, 42 miles downstream, it flattened 300 homes. The final death toll was nearly 500 people, and included 42 pupils at Saugus Elementary School. Initial suspicion fell on saboteurs, but a board of inquiry blamed Mulholland, who had shrugged off warnings that his dam was leaking. His career finished and his reputation shattered, he was heard to mutter in court, "I envy the dead".