It just didn't happen as they expected. The lake did not overwash the levees...the levees failed after the storm.
www.wwltv.com
240 explains it nicely, or as I read on another post, the levies turn to tooth paste in a long hard rain. Having a hard time getting a handle on what these levy breeches mean to N.O. I was told N.O. is divided into sections and that a levy breech would only effect that section. Wish someone could explain just what is happening to New Orleans and what the long term effects will/might be.