Banqiao Dam Collapse 1975
During China's Cultural Revolution in 1975, the Banqiao Dam in Henan Province failed catastrophically under the pounding rain of Typhoon Nina. The storm unleashed a one-in-2,000-year flood that overwhelmed the dam and several others in the region. When Banqiao collapsed, it unleashed a massive wall of water that killed an estimated 170,000 people outright. The disaster destroyed nearly 6 million buildings, left 11 million homeless, and triggered widespread crop failures that later caused famine and more deaths.
In a desperate attempt to prevent even greater destruction, Chinese authorities ordered airstrikes on several downstream dams to redirect floodwaters and protect other structures. The Chinese Communist Party then suppressed news of the disaster for nearly two decades, making the Banqiao collapse one of history's deadliest and least-known engineering failures.