Published almost a decade after one of the most devastating disasters in US history, this cluster of essays on the aftermath of Hurricane Katrina reflects on the hurricane, the measures that could have been taken to prevent the massive devastation caused by it, and the immediate and long-term responses by the government, private industry, and civil society. How has Katrina left a permanent mark not only on the Gulf South but also on our larger national imaginary? What lessons, if any, have we learned, and what actions and policies have we adopted to better mitigate against future disasters? Haunting though the images may be, the flooded homes and emergency rescues from rooftops were not the only impact Katrina had—it altered fundamental social contracts in cities such as New Orleans, from public education to public housing. It also awakened a new activism focused on issues ranging from calls for better levee protection to addressing the loss of wetlands in coastal communities.