In the wake of Hurricane Katrina — a Category 4 hurricane packing 232-kilometers-per-hour winds and a 6-meter storm surge — much of the city of New Orleans is now under water. The Aug. 30 satellite image (directly above), taken by the Moderate Resolution Imaging Spectroradiometer on NASA’s Terra satellite, shows what happened when the storm-damaged levees that protect the city from Lake Pontchartrain (northwest of the city) gave way, flooding the city.

New Orleans officials announced Aug. 31 that about 80 percent of the city was under as much as 3 meters of water. Although New Orleans was most affected by flooding, the hurricane, which came ashore Aug. 29, also left devastation across the neighboring states of Mississippi and Alabama — with Mississippi suffering the most storm damage.

Officials of the American Red Cross, working in concert with the U.S. Federal Emergency Management Agency, called the organization’s plan to house and feed hundreds of thousands of people the biggest response to a single natural disaster in the organization’s 124-year history. With deep flooding that may not recede for weeks in areas across three states, officials said that thousands could remain homeless for more than a year and that the rebuilding would probably take even longer.

The Aug. 27 satellite image (top) shows New Orleans as a tan and green grid sandwiched between the lake shore and the Mississippi River to the south of the city. Three days later, dark pools of water covered the eastern half of the city, and a large section of Lake Pontchartrain ballooned into the region immediately west of the city. In the false-color images obtained from NASA’s Earth Observatory Web site, water is shown as black or dark blue, vegetation is bright green and clouds are light blue and white.