One million flee Katrina's fury

A police car with its rear window broken is abandoned in flood waters in downtown New Orleans in advance of Hurricane Katrina. Picture / Reuters

LOUISIANA - New Orleans was braced early today for the onslaught of Hurricane Katrina which threatened the low-lying city with 250km/h winds and catastrophic damage.

Katrina edged slightly to the east shortly before making landfall near Grand Isle, Louisiana, providing some hope that the worst of the storm's wrath may not be directed at the vulnerable city.

Forecasters feared the powerful storm could drive a surge of water as high as 9m into New Orleans, much of which is below sea level and protected by barriers and pumps.

The northern part of the edge of the hurricane hit shore about 5am central time (10pm NZT), said Martin Nelson, a meteorologist at the US National Hurricane Centre.

Katrina's fury was quickly felt at the Louisiana Superdome, normally home of American professional football's Saints, which became the shelter of last resort for about 9000 of the area's poor, homeless and frail.

Electrical power at the Superdome failed, bringing groans from the crowd. Emergency generators kicked in, but the backup power runs only reduced lighting and is not strong enough to run the air conditioning.

About one million people left the New Orleans area in an unprecedented mandatory evacuation.

The residents fled in bumper-to-bumper traffic.

Early this morning the storm had weakened slightly from category 5 to 4 on the five-step Saffir-Simpson scale. Sustained winds were still reaching 250km/h as it made landfall.

National Hurricane Centre director Max Mayfield predicted the hurricane could weaken slightly.

"But unfortunately this is so large and so powerful that it's a little bit like the difference between being run over by an 18-wheeler or a freight train," he said.

"It's capable of causing catastrophic damage."

If Katrina goes back up to a category 5 hurricane, it would be only the fourth such storm on record to strike the United States.

The head of Jefferson Parish, which includes big suburbs and juts all the way to the storm-vulnerable coast, said some residents who stayed would be fortunate to survive.

"I'm expecting that some people who are die-hards will die hard," said parish council president Aaron Broussard.

Several roads were turned into one-way routes out to speed the evacuation and drivers lined up at petrol stations and stores to buy water and other supplies.

In the French Quarter, shopkeepers sandbagged art galleries and boarded up bars and restaurants in preparation for the storm.

Police and fire officials took to the streets with loudspeakers, alerting residents of the coming danger.

There was little more anyone could do but hope. Streets were empty and bars were closed as gusts up to 90km/h were felt.

The storm held a potential surge of 5.5m to 8.5m that would easily top New Orleans' hurricane protection stopbanks, as well as bigger waves and as much as 38cm of rain.

The fear is that flooding could overrun the levees and turn New Orleans into a toxic lake filled with chemicals and petrol from refineries and waste from septic systems.

New Orleans Mayor Ray Nagin said he expected the pumping system to fail during the height of the storm.

The US Army Corps of Engineers was standing by to get the system running, but water levels must fall first, the mayor said.

"We are facing a storm that most of us have long feared," he said. "This is a once-in-a-lifetime event."

Highways in New Orleans cleared out last night after more than 24 hours of jammed traffic as people headed inland. At the peak of the evacuation, 18,000 people an hour were streaming out of southeastern Louisiana, state police said.

On inland highways in Louisiana and Mississippi, heavy traffic remained the rule into the night as the last evacuees tried to reach safety.

In Orange, Texas, Janie Johnson of the American Red Cross described it as a "river of headlights".

In Washington DC, the Nuclear Regulatory Commission said it had been told that the Waterford nuclear plant, about 32km west of New Orleans, had been shut down as a precaution.

New Orleans has not taken a direct hit from a hurricane since Betsy in 1965, when a 2m to 3m storm surge submerged parts of the city in 2m of water.

Betsy, a category 3 storm, was blamed for 74 deaths in Louisiana, Mississippi and Florida.

Katrina forced energy companies offshore to evacuate personnel and shut platforms in its path. The Gulf of Mexico is home to 25 per cent of the United States' domestic oil and gas output and widespread damage to facilities is possible.

US crude futures jumped about 5 per cent to US$69.65 ($100.45) a barrel after briefly touching a record high of US$70.80 as traders reacted to lost production and fear of damage.

Unleaded petrol futures were up around 8 per cent to US$1.99 a gallon.

None of the four big New Zealand oil companies raised pump prices, but all said they were monitoring the international price.

Tourists on the Gulf Coast scrambled to join the exodus but many were left trapped as rental cars were snapped up quickly.

A New Zealand woman told of a high-speed convoy of taxis that carried 42 Australasian gospel singers to safety.

Wendy Kington from Christchurch said they abandoned plans to hunker down in their New Orleans hotel with food, water and torches and wait the hurricane out.

"We got a dozen taxis to come and drive us 600 miles to Memphis, with all our gear. These taxi drivers were amazing. They actually left their own families to come and get us out.

"So they drove the eight hours ... at breakneck speed, turned around and went back to get their families and get them out of there."

- AGENCIES, STAFF REPORTER