NEW ORLEANS (AP) - Hurricane Katrina plowed into this below-sea-level city Monday with shrieking, 145-mph winds and blinding rain that submerged entire neighborhoods up to the rooflines and peeled away part of the Superdome, where thousands of people had taken shelter. The storm unleashed more chaos as it moved into Mississippi, hurling boats into buildings and ripping billboards to shreds.
Katrina weakened overnight to a Category 4 storm and made a slight turn to the right before hitting land at 6:10 a.m. CDT near the bayou town of Buras. It passed just to the east of New Orleans as it moved inland and later dropped to a 105-mph Category 2 storm, sparing this vulnerable city its full fury.
But destruction was everywhere along Gulf Coast, including an estimated 40,000 homes flooded in St. Bernard Parish just east of New Orleans, said state Sen. Walter Boasso.
Katrina recorded a storm surge of at least 20 feet in Mississippi, where windows of a major hospital were blown out, utility poles dangled in the wind, and casinos were flooded. In some areas, authorities pulled stranded homeowners from roofs or rescued them from attics. In Alabama, exploding transformers lit up the early morning sky as power outages spread.
"Let me tell you something folks. I've been out there. It's complete devastation," said Gulfport Fire Chief Pat Sullivan, who ventured into the hurricane to check threatened areas.
There were no immediate reports of deaths or serious injuries as of midday, but emergency officials have not been able to reach some of the hardest-hit areas. Gov. Haley Barbour said he feared loss of life among those who chose to ignore evacuation orders.
"We know some people got trapped and we pray they are OK," Barbour said.
National Hurricane Center Director Max Mayfield warned that New Orleans would be pounded throughout the day and that Katrina's potential 15-foot storm surge, down from a feared 28 feet, was still enough to cause extensive flooding. Ed Rappaport, deputy director of the hurricane center, estimated that the highest winds in New Orleans were about 100 mph.
"I'm not doing too good right now," Chris Robinson said via cellphone from his home east of the city's downtown. "The water's rising pretty fast. I got a hammer and an ax and a crowbar, but I'm holding off on breaking through the roof until the last minute. Tell someone to come get me please. I want to live."
On the south shore of Lake Ponchartrain, entire neighborhoods of one-story, homes were flooded up to the rooflines. The Interstate 10 off-ramps nearby looked like boat ramps amid the whitecapped waves. Garbage cans and tires bobbed in the water.
Two people were stranded on the roof as murky water lapped at the gutters.
"Get us a boat!" a man in a black slicker shouted over the howling winds.
Across the street, a woman leaned from the second-story window of a brick home and shouted for assistance.
"There are three kids in here," the woman said. "Can you help us?"
Elsewhere along the Gulf Coast, the storm flung boats onto land in Mississippi, lashed street lamps and flooded roads in Alabama, and swamped highway bridges in the Florida Panhandle. At least a half-million people were without power from Louisiana to Florida's Panhandle, including 370,000 in southeastern Louisiana and 116,400 in Alabama, mostly in the Mobile area.
At New Orleans' Superdome, home to 9,000 storm refugees, the wind ripped pieces of metal from the golden roof, leaving two holes that let water drip in. People inside were moved out of the way. Others stayed and watched as sheets of metal flapped and rumbled loudly 19 stories above the floor. Outside, one of the 10-foot, concrete clock pylons set up around the Superdome blew over.
Elsewhere in the city, the storm shattered scores of windows in high-rise office buildings and on five floors of the Charity Hospital, forcing patients to be moved to lower levels. At the Windsor Court Hotel, guests were told to go into the interior hallways with blankets and pillows and to keep the doors to the rooms closed to avoid flying glass.
In suburban Jefferson Parish, Sheriff Harry Lee said residents of a building on the west bank of the Mississippi River called 911 to say the building had collapsed and people might be trapped. He said deputies were not immediately able to check out the building because their vehicles were unable to reach the scene.
At 1 p.m. EDT, Katrina was centered moving to the north at 17 mph.
Katrina was a terrifying, 175-mph Category 5 behemoth - the most powerful category on the scale - before weakening.
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. The Beau Rivage Hotel and Casino, one of the premier gambling spots in Biloxi, had water on the first floor, and Barbour said other casinos were flooded as well.
Katrina was the most powerful storm to affect Mississippi since Hurricane Camille came in as a Category 5 in 1969, killing 143 people along the Gulf Coast.
"This is a devastating hit - we've got boats that have gone into buildings," Gulfport, Miss., Fire Chief Pat Sullivan said as he maneuvered around downed trees in the city. "What you're looking at is Camille II."
In New Orleans' historic French Quarter of Napoleonic-era buildings with wrought-iron balconies, 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.
At the hotel Le Richelieu, the winds blew open sets of balcony French doors shortly after dawn. Seventy-three-year-old Josephine Elow of New Orleans pressed her weight against the broken doors as a hotel employee tried to secure them.
"It's not life-threatening," Mrs. Elow said as rain water dripped from her face. "God's got our back."
Elow's daughter, Darcel Elow, was awakened before dawn by a high-pitched howling that sounded like a trumpeting elephant. "I thought it was the horn to tell everybody to leave out the hotel," she said as she walked the hall in her nightgown.
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, 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.
The National Weather Service reported that a levee broke on the Industrial Canal near the St. Bernard-Orleans parish line, and 3 to 8 feet of flooding was possible. The Industrial Canal is a 5.5-mile waterway that connects the Mississippi River to the Intracoastal Waterway.
Crude oil futures spiked to more than $70 a barrel in Singapore for the first time Monday as Katrina targeted an area crucial to the country's energy infrastructure, but the price had slipped back to $68.95 by midday in Europe. The storm already forced the shutdown of an estimated 1 million barrels of refining capacity.
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 percent heeded the call.
The evacuation itself claimed lives. Three New Orleans nursing home residents died Sunday after being taken by bus to a Baton Rouge church. Officials said the cause was probably dehydration.
New Orleans has not taken a direct hit from a hurricane since Betsy in 1965, when an 8- to 10-foot storm surge submerged parts of the city in seven feet of water. Betsy, a Category 3 storm, was blamed for 74 deaths in Louisiana, Mississippi and Florida.
Katrina hit the southern tip of Florida as a much weaker storm Thursday and was blamed for 11 deaths. It left miles of streets and homes flooded and knocked out power to 1.45 million customers. It was the sixth hurricane to hit Florida in just over a year.
Associated Press reporters Mary Foster, Holbrook Mohr, Brett Martel and Allen G. Breed contributed to this report.