Hurricane Katrina of the 2005 Atlantic hurricane season was the costliest hurricane, as well as one of the five deadliest, in the history of the United States. Among recorded Atlantic hurricanes, it was the sixth strongest overall.

Hurricane Katrina formed over the Bahamas on August 23, 2005 and crossed southern Florida as a moderate Category 1 hurricane, causing some deaths and flooding there before strengthening rapidly in the Gulf of Mexico. The storm weakened before making its second landfall as a Category 3 storm on the morning of Monday, August 29 in southeast Louisiana. It caused severe destruction along the Gulf coast from central Florida to Texas, much of it due to the storm surge. The most severe loss of life and property damage occurred in New Orleans, Louisiana, which flooded as the levee system catastrophically failed, in many cases hours after the storm had moved inland. Eventually 80% of the city became flooded and also large tracts of neighboring parishes, and the floodwaters lingered for weeks.

At least 1,836 people lost their lives in the actual hurricane and in the subsequent floods, making it the deadliest U.S. hurricane since the 1928 Okeechobee hurricane. Economist and crisis consultant Randall Bell wrote: "Hurricane Katrina in 2005 was the largest natural disaster in the history of the United States. Preliminary damage estimates were well in excess of $100 billion, eclipsing many times the damage wrought by Hurricane Andrew in 1992."

The ...