29% by August 28. This scenario was considered a potential catastrophe because some parts of New Orleans and the metro area are below sea level. Since the storm surge produced by the hurricane's right-front quadrant (containing the strongest winds) was forecast to be , while the levees offered protection to , emergency management officials in New Orleans feared that the storm surge could go over the tops of levees protecting the city, causing major flooding. At a news conference at 10 a.m. EDT on August 28, shortly after Katrina was upgraded to a Category 5 storm, New Orleans mayor Ray Nagin ordered the first-ever mandatory evacuation of the city, calling Katrina "a storm that most of us have long feared". The city government also established several "refuges of last resort" for citizens who could not leave the city, including the massive Louisiana Superdome, which sheltered approximately 26,000 people and provided them with food and water for several days as the storm came ashore. Some estimates claimed that 80% of the 1.3 million residents of the greater New Orleans metropolitan area evacuated, leaving behind substantially fewer people than remained in the city during the Hurricane Ivan evacuation. Impact On August 29, 2005, Katrina's storm surge caused 53 breaches to various flood protection structures in and around the greater New Orleans area, submerging 80% of the city. A June 2007 report by the American Society of Civil Engineers indicated that two-thirds of the flooding was caused by the multiple failures of the city's floodwalls. The storm surge also devastated the coasts of Mississippi and Alabama, making Katrina one of the most destructive hurricanes, the costliest natural disaster in the history of the United States (tied with Hurricane Harvey in 2017), and the deadliest hurricane since the 1928 Okeechobee hurricane. The total damage from Katrina is estimated at $125 billion (2005 U.S. dollars). However, in February 2021, a severe winter storm struck the United States, causing at least $195 billion (2021 USD) in damage in Texas. It surpassed both Katrina and Harvey to become the single-costliest natural disaster recorded in the United States. The death toll from Katrina is uncertain, with reports differing by hundreds. According to the National Hurricane Center, 1,836 fatalities can be attributed to the storm: 1 in Kentucky, 2 each in Alabama, Georgia, and Ohio, 14 in Florida, 238 in Mississippi, and 1,577 in Louisiana. However, 135 people remain