William Mulholland was a pioneering Irish-American civil engineer who was instrumental in the development of Los Angeles. As the head of the Los Angeles Department of Water and Power, he masterminded the construction of the massive Los Angeles Aqueduct, which brought water from the Owens Valley to the city. His visionary project enabled the phenomenal growth of Los Angeles in the early 20th century, transforming it from a desert town into a major metropolis. However, his career was tragically marred by the catastrophic 1928 failure of the St. Francis Dam, a disaster for which he publicly accepted full responsibility.