"Hurricane Katrina was the eleventh named storm and the fifth hurricane of the 2005 Atlantic hurricane season. It was the costliest natural disaster and one of the five deadliest hurricanes in the history of the United States."

"The storm originated over the Bahamas on August 23 from the interaction between a tropical wave and the remnants of Tropical Depression Ten. Early the following day, the new depression intensified into Tropical Storm Katrina. The cyclone headed generally westward toward Florida and strengthened into a hurricane only two hours before making landfall at Hallandale Beach and Aventura on August 25. After very briefly weakening to a tropical storm, Katrina emerged into the Gulf of Mexico on August 26 and began to rapidly deepen. The storm strengthened to a Category 5 hurricane over the warm waters of the Gulf of Mexico, but weakened before making its second landfall as a Category 3 hurricane on August 29 in southeast Louisiana."