Los Angeles is standing on the brink of a catastrophic earthquake as this entertainment capital of the world sits on one of the world’s most infamous earthquake hotspots – the San Andreas Fault. How does the city’s buildings and infrastructure survive the onslaught of a destructive earthquake? The city’s leading surveyors and geologists reveal the secrets that keep LA’s skyscrapers standing, protect its roads and aqueducts and prepare its residents for ‘the Big One’. The film explores the geology that shaped the city’s past and challenges its future, from the oil reserves that attracted the first settlers to the fault line where a massive earthquake is long overdue.