Roads were jammed, food was scarce and fuel was running low yesterday as almost two million people tried to escape from southern Texas and Louisiana before Hurricane Rita makes landfall tomorrow.
More than 1.8 million people have been ordered out of their homes to avoid the storm, which threatens to be as strong as Hurricane Katrina, which killed more than 1,000 people on the Gulf Coast last month.
President Bush said federal authorities were "preparing for the worst", putting rescue workers, medical teams and National Guard troops on standby and rushing water, ice and food supplies to the threatened region.
The storm weakened slightly yesterday to a "category 4" hurricane but meteorologists warned it is likely to cause extensive damage along the southern coast of Texas and southwest Louisiana.
The storm is heading towards Texas with winds of over 150mph, stronger than those that battered New Orleans and southern Mississippi. In New Orleans, engineers worked to patch up levees already weakened by Katrina, which could be overwhelmed again by the new hurricane. A plan to repopulate the city was halted earlier this week and all residents have been told to leave immediately.
In Houston, thousands of evacuees from New Orleans who have been sleeping in makeshift shelters were forced to flee once again as they were taken on buses to Arkansas and Tennessee.
Twelve oil refineries on the Gulf Coast have shut, halting 20 per cent of America's refining activity, and Nasa has closed its headquarters south of Houston, handing control of the international space station to the Russians.