What was Hurricane Katrina?

Hurricane Katrina was a powerful Atlantic tropical cyclone that struck the United States Gulf Coast on August 29, 2005, devastating New Orleans, Louisiana and large portions of Mississippi, Alabama, and Florida and becoming one of the deadliest and costliest natural disasters in American history. Katrina formed over the Bahamas on August 23, 2005 and crossed southern Florida as a Category 1 storm on August 25. It then strengthened rapidly over the warm waters of the Gulf of Mexico, reaching Category 5 intensity with sustained winds of 175 miles per hour on August 28. The storm weakened slightly before making its second landfall near Buras, Louisiana on the morning of August 29, 2005 as a strong Category 3 hurricane with sustained winds of about 125 miles per hour.

The greatest damage came not from the wind itself but from the storm surge of up to 28 feet that overwhelmed levees and floodwalls protecting New Orleans. About 80 percent of the city eventually flooded when more than 50 levees failed, in some places days after the storm had passed, sending 8 to 20 feet of water through neighborhoods such as the Lower Ninth Ward, Lakeview, and Gentilly. Roughly 1,200 of the more than 1,800 people killed in the storm died in Louisiana, with most drowned in their homes or attempting to escape. The Mississippi coast was largely flattened by the surge, with cities such as Bay St. Louis, Waveland, and Biloxi suffering catastrophic damage. Total economic damage reached an estimated 125 billion dollars, then a record.

The federal response was widely criticized as slow and disorganized. Tens of thousands of New Orleans residents who could not evacuate sheltered for days at the Louisiana Superdome and the Convention Center without adequate food, water, or sanitation. Federal Emergency Management Agency Director Michael Brown resigned on September 12, 2005 amid criticism, with President George W. Bush's earlier praise that Brownie, you're doing a heck of a job, becoming infamous.

The disaster exposed deep weaknesses in American disaster preparedness, the racial and economic vulnerability of urban poor populations, and the fragility of American levee systems. Reconstruction took years. The Army Corps of Engineers built a new 14.5 billion dollar Hurricane and Storm Damage Risk Reduction System around New Orleans, which has held against subsequent storms. New Orleans's population dropped from about 484,000 before Katrina to around 230,000 a year later and has only partially recovered.