As the center of Hurricane Katrina passed southeast of New Orleans on August 29, 2005, winds downtown were in the Category 1 range with frequent intense gusts. The storm surge caused approximately 23 breaches in the drainage canal and navigational canal levees and flood walls. As mandated in the Flood Control Act of 1965, responsibility for the design and construction of the city's levees belongs to the United States Army Corps of Engineers and responsibility for their maintenance belongs to the Orleans Levee Board. The failures of levees and flood walls during Katrina are considered by experts to be the worst engineering disaster in the history of the United States. By August 31, 2005, 80% of New Orleans was flooded, with some parts under of water. The famous French Quarter and Garden District escaped flooding because those areas are above sea level. The major breaches included the 17th Street Canal levee, the Industrial Canal levee, and the London Avenue Canal flood wall. These breaches caused the majority of the flooding, according to a June 2007 report by the American Society of Civil Engineers. The flood disaster halted oil production and refining which increased oil prices worldwide. Between 80 and 90 percent of the residents of New Orleans were evacuated before the hurricane struck, testifying to some of the success of the evacuation measures. Despite this, many remained in the city, mainly those who did not have access to personal vehicles or who were isolated from the dissemination of news from the local governments. The Louisiana Superdome was used to house and support some of those who were unable to evacuate. Television shots frequently focused on the Superdome as a symbol of the flooding occurring in New Orleans. The disaster had major implications for a large segment of the population, economy, and politics of the entire United States. It has prompted a Congressional review of the Army Corps of Engineers and the failure of portions of the federally built flood protection system which experts agree should have protected the city's inhabitants from Katrina's surge. Katrina has also stimulated significant research in the academic community into urban planning, real estate finance, and economic issues in the wake of a natural disaster. Background New Orleans was settled on a natural high ground along the Mississippi River. Later developments that eventually extended to nearby Lake Pontchartrain were built on fill to bring them above