On August 29, Katrina's storm surge caused 53 different levee breaches in greater New Orleans submerging eighty percent of the city. The storm surge also devastated the coasts of Mississippi and Alabama, making Katrina the most destructive and costliest natural disaster in the history of the United States, and the deadliest hurricane since the 1928 Okeechobee Hurricane.
The confirmed death toll (total of direct and indirect deaths) is 1,836, mainly from Louisiana (1,577) and Mississippi (238).
Federal disaster declarations covered 90,000 square miles (233,000 km?) of the United States, an area almost as large as the United Kingdom. The hurricane left an estimated three million people without electricity. On September 3, 2005, Homeland Security Secretary Michael Chertoff described the aftermath of Hurricane Katrina as "probably the worst catastrophe, or set of catastrophes," in the country's history,