A great American city drowns in a slow-motion disaster. Eyewitness accounts and never-before-seen footage deconstruct the disaster, revealing how 250 billion gallons of water flooded the Big Easy and destroyed more than 150,000 homes. Follow the water from first strike to total deluge and discover the real story behind New Orleans' catastrophe. The most destructive disaster in U.S. history wasn't Hurricane Katrina. It was the chain of events that followed.