Hurricane Katrina Hurricane Katrina was the deadliest and most destructive Atlantic hurricane of the 2005 Atlantic hurricane season. It was the costliest natural disaster, as well as one of the five deadliest hurricanes, in the history of the United States. Among recorded Atlantic hurricanes, it was the sixth strongest overall. At least 1,833 people died in the hurricane and subsequent floods, making it the deadliest U.S. hurricane since the 1928 Okeechobee hurricane; total property damage was estimated at $81 billion (2005 USD), nearly triple the damage wrought by Hurricane Andrew in 1992. Hurricane Katrina formed over the Bahamas on August 23, 2005 and crossed southern Florida as a moderate Category 1 hurricane, causing some deaths and flooding there before strengthening rapidly in the Gulf of Mexico. The hurricane strengthened to a Category 5 hurricane over the warm Gulf water, but weakened before making its second landfall as a Category 3 hurricane on the morning of Monday, August 29 in southeast Louisiana. It caused severe destruction along the Gulf coast from central Florida to Texas, much of it due to the storm surge. The most significant number of deaths occurred in New Orleans, Louisiana, which flooded as the levee system catastrophically failed, in many cases hours after the storm had moved inland. Eventually 80% of the city and large tracts of neighboring parishes became flooded, and the floodwaters lingered for weeks. However, the worst property damage occurred in coastal areas, such as all Mississippi beachfront towns, which were flooded over 90% in hours, as boats and casino barges rammed buildings, pushing cars and houses inland, with waters reaching 6–12 miles (10–19 km) from the beach. On August 29, Katrina's storm surge caused 53 different levee breaches in greater New Orleans, submerging eighty percent of the city. A June 2007 report by the American Society of Civil Engineers indicated that two-thirds of the flooding were caused by the multiple failures of the city's floodwalls. Not mentioned were the flood gates that were not closed.[citation needed] The storm surge also devastated the coasts of Mississippi and Alabama, making Katrina the most destructive and costliest natural disaster in the history of the United States, and the deadliest hurricane since the 1928 Okeechobee Hurricane. The total damage from Katrina is estimated at $81.2 billion (2005 U.S. dollars), nearly double the cost of the previously most expensive storm, Hurricane Andrew, when adjusted for inflation. The confirmed death toll (total of direct and indirect deaths) is 1,836, mainly from Louisiana (1,577) and Mississippi (238). However, 135 people remain categorized as missing in Louisiana, and many of the deaths are indirect, but it is almost impossible to determine the exact cause of some of the fatalities. Federal disaster declarations covered 90,000 square miles (233,000 km2) of the United States, an area almost as large as the United Kingdom. The hurricane left an estimated three million people without electricity. On September 3, 2005, Homeland Security Secretary Michael Chertoff described the aftermath of Hurricane Katrina as "probably the worst catastrophe, or set of catastrophes," in the country's history, referring to the hurricane itself plus the flooding of New Orleans. Even in 2010, debris remained in some coastal communities. The economic effects of the storm were far-reaching. The Bush Administration sought $105 billion for repairs and reconstruction in the region, which did not account for damage to the economy caused by potential interruption of the oil supply, destruction of the Gulf Coast's highway infrastructure, and exports of commodities such as grain. Katrina damaged or destroyed 30 oil platforms and caused the closure of nine refineries;[39] the total shut-in oil production from the Gulf of Mexico in the six-month period following Katrina was approximately 24% of the annual production and the shut-in gas production for the same period was about 18%. The forestry industry in Mississippi was also affected, as 1.3 million acres (5,300 km2) of forest lands were destroyed. The total loss to the forestry industry from Katrina is calculated to rise to about $5 billion. Furthermore, hundreds of thousands of local residents were left unemployed, which will have a trickle-down effect as fewer taxes are paid to local governments. Before the hurricane, the region supported approximately one million non-farm jobs, with 600,000 of them in New Orleans. It is estimated that the total economic impact in Louisiana and Mississippi may exceed $150 billion. Katrina redistributed over one million people from the central Gulf coast elsewhere across the United States, which became the largest diaspora in the history of the United States. Houston, Texas, had an increase of 35,000 people; Mobile, Alabama, gained over 24,000; Baton Rouge, Louisiana, over 15,000; and Hammond, Louisiana received over 10,000, nearly doubling its size. Chicago received over 6,000 people, the most of any non-southern city. By late January 2006, about 200,000 people were once again living in New Orleans, less than half of the pre-storm population. By July 1, 2006, when new population estimates were calculated by the U.S. Census Bureau, the state of Louisiana showed a population decline of 219,563, or 4.87%. Additionally, some insurance companies have stopped insuring homeowners in the area because of the high costs from Hurricanes Katrina and Rita, or have raised homeowners' insurance premiums to cover their risk. Katrina also had a profound impact on the environment. The storm surge caused substantial beach erosion, in some cases completely devastating coastal areas. In Dauphin Island, approximately 90 miles (150 km) to the east of the point where the hurricane made landfall, the sand that comprised the barrier island was transported across the island into the Mississippi Sound, pushing the island towards land. The storm surge and waves from Katrina also obliterated the Chandeleur Islands, which had been affected by Hurricane Ivan the previous year. The US Geological Survey has estimated 217 square miles (560 km2) of land was transformed to water by the hurricanes Katrina and Rita. The lands that were lost were breeding grounds for marine mammals, brown pelicans, turtles, and fish, as well as migratory species such as redhead ducks. Overall, about 20% of the local marshes were permanently overrun by water as a result of the storm. The storm caused oil spills from 44 facilities throughout southeastern Louisiana, which resulted in over 7 million U.S. gallons (26 million L) of oil being leaked. Some spills were as small as a few hundred gallons; the largest are tabulated to the right. While most of the spills were contained on-site, some oil entered the ecosystem, and the town of Meraux was flooded with a blend of water and oil.[86] Unlike Hurricane Ivan no offshore oil spills were officially reported after Hurricane Katrina. However, Skytruth reported some signs of surface oil in the Gulf of Mexico. Finally, as part of the cleanup effort, the flood waters that covered New Orleans were pumped into Lake Pontchartrain, a process that took 43 days to complete. These residual waters contained a mix of raw sewage, bacteria, heavy metals, pesticides, toxic chemicals, and oil, which sparked fears in the scientific community of massive numbers of fish dying.