Tuesday, Aug. 22, 2023 at 9 p.m. on KPBS TV / Stream now with the PBS App + Encore Wednesday, Aug. 30 at 8 p.m. on KPBS 2. Explore the 1928 dam collapse, the second deadliest disaster in California history. A colossal engineering failure, the dam was built by William Mulholland to ensure the growth of Los Angeles by bringing water to the city via aqueduct.