Mayor Ray Nagin has ordered a mandatory evacuation of New Orleans, directing residents of a city still recovering from the devastation left behind three years ago from Hurricane Katrina to flee from the approaching Hurricane Gustav.
Mr Nagin said an informal evacuation that has taken place for days becomes mandatory at 8am local time today on the city’s west bank.
It becomes mandatory on the east bank at noon.
The announcement comes as officials continued to evacuate the elderly, disabled, poor and others without means ahead of Gustav's march toward the Gulf Coast.
Officials began putting an estimated 30,000 of such residents on buses and trains, as Mr Nagin also called on all tourists to leave.
Mr Nagin called Gustav ``the storm of the century'' and told residents to ``get your butts out of New Orleans now''.
“This is the real deal, not a test,” Mr Nagin said as he issued the order, warning residents that staying would be “one of the biggest mistakes of your life”.
He emphasised that the city will not offer emergency services to anyone who chooses to stay behind.
Gustav had already killed more than 80 people in the Caribbean, and if current forecasts hold up, it would make landfall on Monday afternoon somewhere between the East Texas and western Mississippi.
Forecasters at the National Hurricane Centre said they were surprised at how quickly Gustav gained strength as it slammed into Cuba’s tobacco-growing western tip.
It went from a tropical storm to a Category 4 hurricane in about 24 hours, and was likely to become a Category 5 – with sustained winds of 156 mph (251 kph) or more.
“That puts a different light on our evacuations and hopefully that will send a very clear message to the people in the Gulf Coast to really pay attention,” said Federal Emergency Management Agency chief David Paulison.
Levee building on the city’s west bank was incomplete, Mr Nagin said. A storm surge of 15 to 20 feet would pour through canals and flood the neighbourhood and neighbouring Jefferson Parish, he said.