Great Chicago Flood 20th Anniversary
What sets the Great Chicago Flood apart from other floods is that it happened a mere 20 years ago. Millions of gallons of water broke through an old underground tunnel, 20 feet below the bed of the Chicago River, flooding the city's business district on April 13, 1992. "Over 200 million gallons of water surged through an extensive series of underground tunnels, affecting more than 30 major buildings, including City Hall and the financial markets. Lower levels of major office high-rises held up to 40 feet of water, and the city center was evacuated out of fear that electrical or utility connection failures could endanger lives ... causing estimated damages of $2 billion," according to Exponent Engineering.