Time was running out for New Orleans residents yesterday to escape the fury of Hurricane Gustav, which mayor Ray Nagin has called "the mother of all storms".

The compulsory evacuation of the city is under way after orders from Nagin on Saturday night. No vehicles are allowed to drive into New Orleans.

Gustav forced President George W. Bush to skip the Republican Party convention where John McCain would be officially nominated as the presidential candidate.

It is almost three years to the day since Hurricane Katrina swept through the birthplace of jazz, killing hundreds and exposing deep poverty and lack of preparation.

Hurricane Gustav is churning toward the Louisiana coast through the oil-rich Gulf of Mexico, with strength that could rival Hurricane Katrina.

Yesterday morning, Alabama Governor Bob Riley, too, warned residents of the dangers of Hurricane Gustav, and ordered mandatory evacuations in parts of the coastal area.

Nagin asked New Orleans' more than 239,000 residents to leave the city to escape the wrath of the worst hurricane since Katrina.

"This is the mother of all storms," Nagin said of Gustav, a monstrous storm that was forecast to approach the central Louisiana coast just west of New Orleans on Sunday.

"You need to be concerned and you need to get your butts moving and out of New Orleans right now," Nagin said at City Hall. "This is the storm of the century."

The evacuation started with the city's low-lying West Bank around 8 am yesterday, followed by the East Bank around noon.

Residents have the choice to remain behind and weather the storm, but "that would be one of the biggest mistakes that you could make in your life", Nagin said.

He said people might have to chop through the roofs of their houses to escape rising waters if they stay. "Make sure you have an axe," he said.

Thousands of people had started fleeing the city even before Nagin's order to avoid a repeat of the Katrina disaster. The government lined up hundreds of buses and trains to evacuate 30,000 people who could not leave on their own.

Questions:

1. When did Hurricane Katrina hit New Orleans?

2. Why does New Orleans mayor Ray Nagin call Hurricane Gustav “the mother of all storms”?

3. How is the government helping people evacuate the area?

Answers:

1. Three years ago.

2. It is believed the strength of Hurricane Gustav could rival Hurricane Katrina.

3. The government is providing buses and trains to evacuate 30,000 people who cannot do so on their own.