Hurricane Katrina

Hurricane Katrina was an extremely powerful and catastrophic tropical cyclone that affected the Southeastern United States in late August 2005, particularly in and around the city of New Orleans. Katrina became the United States' costliest tropical cyclone, with an estimated $125 billion ($206 billion when adjusted for inflation) in damages. The hurricane killed 1,392 people, making it the deadliest American hurricane since the 1928 Okeechobee hurricane. Katrina was the twelfth tropical cyclone, the fifth hurricane, the third major hurricane, and the second Category 5 hurricane of the 2005 Atlantic hurricane season. It was also the fourth-most intense Atlantic hurricane to make landfall in the contiguous United States, as measured by barometric pressure.

The hurricane originated on August 23 near the Bahamas, from the merger of a tropical wave and the remnants of a tropical depression. Katrina strengthened into a hurricane before making its first landfall in southeast Florida on August 25. Crossing the state, the hurricane entered the Gulf of Mexico on August 26 and rapidly intensified. Early on August 28, Katrina peaked as a Category 5 hurricane, with winds of 175 mph (280 km/h) and a minimum central pressure of 902 mbar (26.64 inHg). Turning to the north, the hurricane weakened to a Category 3 hurricane before making landfall on August 29 near Buras-Triumph, Louisiana, with a subsequent final landfall near the Louisiana–Mississippi border. Katrina also produced a widespread tornado outbreak while moving inland and weakening. On August 31, a cold front over Ohio absorbed the circulation of the former hurricane. The remnants of Katrina continued to the northeast, later moving through Canada before losing their identity on September 7 near Greenland.

Eighty percent of New Orleans, as well as large areas in neighboring parishes, were flooded. It is estimated that about 100,000 to 150,000 people remained in the City of New Orleans, despite mandatory evacuation orders. The flooding prompted a massive national and international response effort, including federal, local, and private rescue operations. The largest loss of life was due to flooding caused by engineering flaws in the federally built hurricane protection system, particularly the levees around New Orleans. Investigators concluded that the U.S. Army Corps of Engineers, tasked by Congress in the Flood Control Act of 1965 to design and build the region's hurricane protection, was responsible for the breached floodwalls. Later, a federal appeals court ruled that the Army Corps, despite being responsible, could not be held financially liable due to the Flood Control Act of 1928.

The emergency response from federal, state, and local governments was widely criticized, leading to the resignation of Federal Emergency Management Agency (FEMA) director Michael D. Brown and New Orleans Police Department (NOPD) superintendent Eddie Compass. Many other government officials faced criticism for their responses, especially New Orleans mayor Ray Nagin, Louisiana governor Kathleen Blanco, and President George W. Bush. However, several agencies, such as the United States Coast Guard (USCG), National Hurricane Center (NHC), and National Weather Service (NWS), were commended for their actions, with the NHC being particularly praised for its accurate forecasts well in advance. The destruction and loss of life caused by the storm prompted the name Katrina to be retired by the World Meteorological Organization in April 2006.