21st Century
In early 2001, the Federal Emergency Management Agency (FEMA), named three major scenarios as being among the most serious threats to the nation: (1) a major hurricane hitting New Orleans, (2) a terrorist attack in New York City, and (3) a large earthquake hitting San Francisco. In 2004, a Corps of Engineers' study was done on the costs and feasibility of protecting southeast Louisiana from a major Category 5 hurricane, including construction of floodgate structures and raising existing levees. The report also suggested that the chances of a major Category 5 hurricane directly striking New Orleans was a one-in-500 year event.
Read more about this topic: Hurricane Preparedness For New Orleans