Hurricane Katrina is weakening as it moves north, but leaves a wide trail of damage in several U.S. states on the Gulf of Mexico.
The National Weather Service has downgraded Katrina to a category two hurricane, still packing winds of 170 kilometers per hour.
Officials are just beginning to assess its effects. The weather service says Katrina caused "extensive damage" in the city of New Orleans and "extreme damage" in coastal areas of the state of Mississippi.
Video from New Orleans shows streets covered with debris and ankle-deep water. Higher flooding is reported on the city's east side.
Heavy flooding is also reported in Biloxi and Gulfport, Mississippi, where witnesses say sailboats have been washed ashore. Hundreds of thousands of people across the region are without power.
Katrina made landfall for the second time today (Monday). Last week it hit the southern U.S. state of Florida, where it is blamed for at least seven deaths.
The storm gained strength as it tracked through the Gulf of Mexico, coming ashore today as one of the most powerful hurricanes to hit the United States.