By now you know that engineers had long predicted the cataclysmic flooding that struck New Orleans. But what you might not realize is that Katrina-a category-4 cyclone when it made landfall in Louisiana on August 29-was not the worst-case scenario. That would be a direct hit from a category-5 hurricane, which would send a storm surge over the city's levees and submerge New Orleans in minutes. Anyone who had ignored evacuation orders would drown.
New Orleans needs more protection than levees alone can offer.