More than a million people were preparing to leave Houston and southern Texas last night as Hurricane Rita

As the death toll from Hurricane Katrina passed 1,000, oil prices hit $68 a barrel and Rita, potentially more powerful, bore down on the Texas coast. It is expected to hit land on Saturday.

Officials in New Orleans issued a warning that even 3in of rain could overwhelm the damaged protective levees. Army engineers worked round the clock to make repairs.

Rita, with wind speeds of 165mph, is expected to make landfall southeast of Houston, near the coastal city of Galveston, the scene of a hurricane that killed up to 12,000 people in 1900. Standing in its presumed path are three of the country’s five largest refineries.

Nasa ordered the evacuation of the Johnson Space Centre in Houston and turned over control of the International Space Station to its Russian partners as most of its staff fled from Rita. President Bush, declaring a state of emergency in Louisiana and Texas, said: “We’ve got to be ready for the worst.”

Bill White, the Mayor of Houston, called for residents in low-lying, flood-prone areas of the city to leave, and asked them to help neighbours who could not move themselves. Rick Perry, the Governor of Texas, ordered 5,000 National Guardsmen and 1,000 state troopers into position.

The White House, federal officials and state and local politicians, chastened by the political and psychological impact of Katrina, promised that lessons had been learnt in New Orleans. Last night the poor and infirm were already being evacuated from Rita’s likely landfall, and a huge military and federal aid programme had begun.

By last night, 2,000 poor and infirm residents in Galveston had left the city by bus. Officials urged them to carry prescriptions to last at least three months. David Paulison, the acting director of the Federal Emergency Management Agency, said that the Pentagon had set up a military field hospital in Texas and a field kitchen able to serve 5,000 meals a day, Times Online reports.