US: Thousands of people began evacuating the southern US city of New Orleans yesterday as Hurricane Katrina bore down with winds up to 175 mph and the threat of a massive storm surge.
The mayor, Ray Nagin, ordered an immediate evacuation of the entire city of 485,000, which is below sea level.
Acknowledging that large numbers of people, many of them stranded tourists, would be unable to leave before the eye of the storm struck land later today, the city set up 10 "places of last resort", including the Louisiana Superdome arena.
"The city of New Orleans has never seen a hurricane of this magnitude hit it directly," Mr Nagin said. "We are facing a storm that most of us have long feared."
The mayor urged people who chose to go to the superdome to take enough food and supplies to last three to five days. He said that police and fire-fighters were patrolling the city and suburbs, telling residents to get out. He added that police would have the authority to commandeer any vehicle or building which could be used for evacuation or shelter.
Hotels were exempted from the evacuation order because airlines had cancelled all flights out of New Orleans.
The mayor said that a direct hit by Katrina's storm surge would breach the levees which protect the city from the surrounding water of Lake Pontchartrain, the Mississippi River and marshes. The bowl-shaped city has to pump water out even during normal times and the hurricane could cut off the electricity supply which powers these pumps.
As he prepared the federal government for a massive relief effort, President George W. Bush urged people in the path of the hurricane to forget anything but their safety and move to higher ground, as instructed.
Rain started falling on the south-eastern tip of Louisiana at midday yesterday as the storm moved across the Gulf of Mexico towards land. Highways in Mississippi and Louisiana were jammed as people headed away from Katrina's expected landfall.
Beyond the Gulf Coast, Katrina was "unmitigated bad news for consumers", because it had shut down offshore production of at least one million barrels of oil daily and was threatening refinery and import operations around New Orleans, said Peter Beutel, an oil analyst in New Canaan, Connecticut. He predicted that crude oil would top $70 a barrel by later today or tomorrow.
If Katrina maintains its strength, it will be only the fourth Category 5 hurricane on record to strike the US.
The superdome began taking in people with special needs yesterday morning. Residents using walking frames, some carrying oxygen tanks, began checking in when it opened at 8 am local time.
Yesterday afternoon, the National Hurricane Centre in Miami said that Katrina's maximum sustained wind speed had stepped up to nearly 175 mph, with higher gusts.
The hurricane's eye was estimated to be about 225 miles south-east of the mouth of the Mississippi River by late yesterday afternoon. The storm was moving towards land at nearly 12 mph and was expected to turn to the north-west.
Forecasters said that weather conditions around the coast would become very turbulent during the night, but they could not say when the eye of the storm would strike land.
A hurricane warning was in effect for the north-central Gulf Coast from Morgan City, Louisiana, to the Alabama/Florida state line, meaning that hurricane conditions were expected within 24 hours, the Hurricane Centre said. Tropical storm warnings extended along a coastal span of about 480 miles.
Storm surges of up to 28 feet, topped by waves up to 30 feet, were possible in some areas, meteorologist Chris Sisko said. As much as 15 inches of rain also was possible.
Only three Category 5 hurricanes - the highest on the Saffir-Simpson scale - have hit the US since record-keeping began. The last was Hurricane Andrew in 1992, which levelled parts of south Florida, killed 43 people and caused $31 billion in damage. The others were the 1935 hurricane which hit the Florida Keys and killed 600 people and Hurricane Camille, which devastated the Mississippi coast in 1969, killing 256 people.
Katrina's landfall could still come in Mississippi and affect Alabama and Florida, but it looked likely to come ashore on the Louisiana coast, said Ed Rappaport, deputy director of the Hurricane Centre. That put New Orleans directly in the firing line.
"If it came ashore with the intensity it has now and went to the New Orleans area, it would be the strongest we've had in recorded history there," Mr Rappaport said. "We're hoping that there will be a slight tapering off at least of the winds, but we cannot plan on that. So whichever area gets hit, this is going to be a once-in-a-lifetime event."
Mandatory evacuations were ordered all along the Mississippi coast, where casinos were closed yesterday. National Guard units had already been deployed, state officials said.
Residents of several barrier islands in the western Florida Panhandle were also advised to evacuate yesterday. "The water is already up to the backs of homes on Pensacola Beach and Perdido Key," said Sonya Smith, a spokeswoman for Escambia County in Florida.
Katrina has already been blamed for nine deaths in south Florida. It is the sixth hurricane to hit the state in just over a year.