Storm unleashes fury on US Gulf Coast

Adam Nossiter, New Orleans

Katrina weakened overnight to a Category 4 storm and made a slight turn to the right before coming ashore at 6.10am CDT near the Louisiana bayou town of Buras. The storm passed just to the east of New Orleans as it moved inland, sparing the vulnerable below-sea-level city its full fury and the apocalyptic damage forecasters had feared.

But there was destruction everywhere along the Gulf Coast, including an estimated 40,000 homes flooded in St Bernard Parish just east of New Orleans.

Katrina recorded a storm surge of more than 20 feet in Mississippi, where windows of a major hospital were blown out and billboards were ripped to shreds. In some areas, authorities pulled stranded homeowners from roofs or rescued them from attics. In Alabama, exploding transformers lit up the early morning sky and muddy, six-foot waves engulfed stately, million-dollar homes along Mobile Bay's normally tranquil waterfront.

"Its complete devastation," said Mississippi fire chief Pat Sullivan.

Emergency officials were unable to reach some of the hardest-hit areas to determine the number of injuries or deaths. Officials across the region sent water rescue teams out and stood ready to dispense ice, water and meals to hurricane-stricken residents.

"We know some people got trapped and we pray they are okay," Governor Haley Barbour said.

At 3pm EDT, a rapidly weakening Katrina was centred about 20 miles southwest of Hattiesburg, Mississippi, moving northward at about 19mph. Its winds had dropped to about 95mph, making it a Category 1 storm.

Ed Rappaport, deputy director of the hurricane centre, estimated that the highest winds in New Orleans were about 100 mph. Louisiana Governor Kathleen Blanco said her office had reports of as many 20 building collapses in New Orleans, and scores of residents stranded in attics or on rooftops. On the south shore of Lake Ponchartrain, entire neighbourhoods of one-storey homes were flooded up to the rooflines. The Interstate 10 off-ramps nearby looked like boat ramps amid the whitecapped waves.

Two people were stranded on the roof as murky water lapped at the gutters.

At least a half-million people were without power from Louisiana to Florida's Panhandle, including 370,000 in southeastern Louisiana and well over 100,000 each in Alabama and Mississippi.

At New Orleans' Superdome, home to 9,000 storm refugees, the wind ripped pieces of metal from the roof.

People inside were moved out of the way. Others stayed and watched as sheets of metal flapped and rumbled loudly 19 storeys above the floor.

By midday, the brunt of the storm had moved beyond New Orleans to Mississippi's coast, home to the state's floating casinos, where Katrina washed sailboats onto a coastal four-lane highway.

Katrina was the most powerful storm to affect Mississippi since Hurricane Camille came in as a Category 5 in 1969, killing 256 people in Louisiana and Mississippi.

"This is a devastating hit we've got boats that have gone into buildings," said Mr Sullivan, the Gulfport fire chief. "What you're looking at is Camille II."

In New Orleans' historic French Quarter water pooled in the streets from the driving rain, but the area appeared to have escaped the catastrophic flooding that forecasters had predicted.

On Jackson Square, two massive oak trees outside the 278-year-old St Louis Cathedral came out by the roots, ripping out a 30-foot section of ornamental iron fence and straddling a marble statue of Jesus Christ, snapping off only the thumb and forefinger of his outstretched hand.

For years, forecasters have warned of the nightmare scenario a big storm could bring to New Orleans, a bowl of a city that is up to 10 feet below sea level in spots and relies on a network of levees, canals and pumps to keep dry from the Mississippi River on one side and Lake Pontchartrain on the other.

The fear was that flooding could overrun the levees and turn New Orleans into a toxic lake filled with chemicals and petroleum from refineries, as well as waste from ruined septic systems.

Governor Blanco took little comfort in the fact that the hurricane may have spared New Orleans much worse flooding, given the still uncertain toll in surrounding parishes.

"I can't say that I feel that sense that we've escaped the worst," she said. "I think we don't know what the worst is right now."

Calling it a once-in-a-lifetime storm, New Orleans Mayor Ray Nagin had ordered a mandatory evacuation over the weekend for the 480,000 residents of the vulnerable city, and he estimated about 80% heeded the call.

The evacuation itself claimed lives. Three New Orleans nursing home residents died on Sunday after being taken by bus to a Baton Rouge church. Officials said the cause was probably dehydration.