The cost of Ike's progress along the Gulf Coast could reach $22 billion, National Geographic News reported, making it the third most costly U.S. hurricane, lagging behind Hurricane Katrina in 2005 and Hurricane Andrew in 1992.

Relief trucks begun rolling into Texas, bringing ice, water and food, the Christian Science Monitor reported.

On Galveston Island, search and rescue officials said health conditions were deteriorating and mosquitoes were becoming a serious problem, the Houston Chronicle said. One man with about 1,000 mosquito bites had to be airlifted out.

Meanwhile, the U.S. Environmental Protection Agency said it allow the suspension of Texas low emission requirements for diesel engines until Sept. 30, but federal regulations for ultra low sulfur diesel fuel must still be met.

The EPA said it granted the waiver, in coordination with the Department of Energy, to allow "greater flexibility for fuel distribution systems in the affected areas."

U.S. Homeland Security Secretary Michael Chertoff warned of possible "unpleasant surprises" as boat and helicopter rescue crews slogged through the debris fields of Galveston and Crystal Beach.

Galveston City Manager Steve LeBlanc said 15,000-20,000 residents of a population of about 60,000 were on the island Monday, while about 3,000 were trying to evacuate.

Buses have been taking residents to shelters in San Antonio, LeBlanc said, adding that Austin expressed willingness to accept more evacuees.

"The bottom line is that Galveston can't adequately accommodate its population," he said.

"Do not come back to Galveston," Mayor Lyda Ann Thomas warned those who evacuated to escape the storm. "You cannot live here at this time."