1755 Lisbon Earthquake

The Great Lisbon Earthquake struck on All Saints' Day while churches across the city were filled with worshippers and lit candles, triggering fires that raged for five days. A massive tsunami with waves up to 20 meters high surged up the Tagus River 40 minutes later, drowning survivors who had fled to the waterfront. The disaster profoundly influenced Enlightenment philosophy, inspired Voltaire's Candide, and is considered the birth of modern seismology and earthquake engineering under the Marquis de Pombal's reconstruction.