New Orleans evacuated as ferocious Hurricane Katrina nears

ORLEANS, Monday (AFP) Tens of thousands of people fled New Orleans amid fears of catastrophe as Hurricane Katrina barreled toward the low-lying southern US city with winds of 257 kilometers per hour.

"We are facing the storm that most of us have feared," New Orleans Mayor Ray Nagin said as he issued an unprecedented mandatory evacuation order for the city known as "The Big Easy."

"I do not want to create panic. But I do want the citizens to understand that this is very serious and it's of the highest nature," Nagin said.

Katrina, which looked set to make landfall around 7:00 am (1100 GMT) Monday, has become a rare, "potentially catastrophic," category-five storm, at the top of the Saffir-Simpson hurricane intensity scale, the National Hurricane Center (NHC) said.

Katrina ranked only at category one when it slammed ashore Thursday in south Florida, where it killed seven people before heading out to the oil-rich Gulf of Mexico.

"We need to pray, of course, very strongly, that the hurricane force would diminish," said Louisiana state Governor Kathleen Blanco.

US President George W. Bush declared a state of emergency that clears the way for federal aid, and urged people to get out of the hurricane's path.

"We cannot stress enough the dangers this hurricane poses to Gulf Coast communities. I ask citizens to put their safety and the safety of their families first by moving to safe ground," Bush said from his Texas ranch.

Highways were gridlocked Sunday as tens of thousands of people fled New Orleans and other coastal areas. Because much of the city of 1.4 million people is below sea level, it is highly prone to flooding. Nagin feared flood embankments would not withstand the ferocity of the hurricane. Max Mayfield, the National Hurricane Center director, warned that the biggest threats were not wind or rain, but rising Gulf waters.

"People need to understand that the greatest potential for large loss of life is from the storm surge flooding near the coastline," Mayfield told CNN.

At the city's Louis Armstrong airport, people anxiously awaited outbound flights.

"I'm just happy to be getting out of here," said Tracy Roberson, a 31-year-old postal worker who sat at the airport with her cat. "I think there's going to be casualties because they didn't give enough notice."

Some 30,000 people took refuge in the Superdome sports arena, which authorities designated a shelter of last resort for those unable to flee the city.

Authorities also ordered evacuations in neighboring Mississippi, which expected to be slammed by the monster storm that gathered energy from the warm Gulf of Mexico as it neared land.