New Orleans 1980s and 1990s, scientists observed that extensive, rapid, and ongoing erosion of the marshlands and swamp surrounding New Orleans, especially that related to the Mississippi River – Gulf Outlet Canal, had the unintended result of leaving the city more vulnerable than before to hurricane-induced catastrophic storm surges. New Orleans was catastrophically affected by what Raymond B. Seed called "the worst engineering disaster in the world since Chernobyl", when the Federal levee system failed during Hurricane Katrina in 2005. By the time the hurricane approached the city at the end of August 2005, most residents had evacuated. As the hurricane passed
Hurricane preparedness for New Orleans Hurricane Ivan's threat to the city resulted in the largest evacuation of the city to date. Mayor Ray Nagin issued a call for a voluntary evacuation of the city at 6 pm on September 13. An estimated 600,000 or more evacuated from Greater New Orleans. The contraflow plan was put into full effect for the first time, but rather late in the evacuation due to various confusions. This proved valuable practice, for the contraflow was implemented much more smoothly in 2005. Hurricane Pam was a hypothetical hurricane used as a disaster scenario to drive planning for a 13-parish area in