The effect of Hurricane Katrina on New Orleans was catastrophic and long-lasting. The storm, which was the costliest hurricane as well as one of the deadliest natural disasters in U.S. history, made its second and third landfalls in the Gulf Coast region on August 29, 2005 as a powerful Category 3 hurricane (with a storm surge of a Category 5 hurricane). By August 31, 2005, eighty percent (80%) of the city was flooded, with some parts under 20 feet (6.1 meters) of water. Four of the city's protective levees were breached, including the 17th Street Canal levee, the Industrial Canal levee, and the London Avenue Canal floodwall.