How many people were left homeless after Hurricane Katrina?

According to a 2006 Census Bureau study, the damage left by Hurricane Katrina caused over 400,000 people throughout the Gulf Coast region to lose their homes. Many former residents remain displaced as of 2014, as the affected areas are still in the process of redevelopment.

Although Katrina affected over 90,000 square miles of the Gulf Coast, New Orleans residents were the most heavily affected by the storm, as the city's system of levees was poorly equipped to handle the stresses of a powerful hurricane. Moreover, the city's average elevation is 6 feet below sea level, forming a basin into which nearby bodies of water drained when engorged by the torrential downpours.