Case History:

Katrina remains one of the deadliest and costliest hurricanes in U.S. history, with more than 1,800 lives lost and damages estimated at over $100 billion. When the levees failed, about 80 percent of New Orleans flooded. More than 1 million people across the Gulf Coast were forced to leave their homes — many never returned.

An independent levee investigation team final report was issued on July 31, 2006. This report contained the observations and findings of an investigation by an independent team of professional engineers and researchers with a wide array of expertise (Report Link)

Please review the following materials:
Overview of Hurricane Katrina and its aftermath (Chapter 2, posted)
Geology of the New Orleans Regions (Chapter 3 )
History of the New Orleans Flood Protection System (Chapter 4,)
Summary of Engineering Lessons (Chapter 11, posted )
Sea-Level Rise and Subsidence: Implications for Flooding in New Orleans, Louisiana (USGS Paper)