The Brief Hurricane Katrina struck New Orleans on August 29, 2005, ultimately killing roughly 1,800 people and causing massive flooding. Survivors, first responders and investigators reflect on failures and the lessons learned — two decades later. Katrina hit New Orleans with 125 mph winds, unleashing severe flooding after levee breaches. RELATED: America after Katrina: Eyewitness to disasterTimeline:August 29, 2005: Katrina hit New Orleans and levees failed, causing flooding to spread across the city. Why you should care:Katrina was not just a natural disaster — it revealed failures in engineering, emergency response and government planning.