Forecasters say an increasingly fierce Hurricane Rita is on track to hit the U.S. state of Texas, and could affect areas ravaged by Hurricane Katrina three weeks ago.
At last report, Rita was churning west through the Gulf of Mexico, with winds of 225 kilometers per hour.
Texas Governor Rick Perry has called on residents of the state's long Gulf coastline to move inland before Rita makes its expected landfall early Saturday.
Evacuations had already begun in low-lying Galveston, which was nearly destroyed by a hurricane in 1900.
In New Orleans, engineers are racing to strengthen the fractured levee system that failed to hold back floodwaters from Katrina.
The city sits east of Hurricane Rita's target area, but officials warn it would take just eight centimeters of rain to overwhelm the levees and cause more flooding.
The U.S. National Hurricane Center says Rita could strengthen from a category-four to a rare category-five storm within the next 24 hours.