Today along the shoreline the calm and placid waters of the Gulf Coast belie the destructive force that was Katrina.
The three-tiered system begins with local drainage off yards and streets, moves into municipal and county storm drains, and is then deposited into the water management district structures.
A 180-ton chunk of steel crushed a neighborhood grocery store. Cars were flipped onto their roofs. A wooden plank was hurled with such force it pierced a brick wall.