WASHINGTON, Aug. 30 (Xinhuanet) -- Hundreds are feared dead on Tuesday after Hurricane Katrina ravaged the US Gulf Coast in what officials have called one of the worst storms in US history.

    Television images showed homes that were reduced to piles of wood when Katrina ripped the southeastern coast Monday.

    As waters rose in New Orleans after the storm hit, the White House said President George W. Bush returned early to Washington from his Texas vacation to focus on hurricane relief.

    Bush declared Louisiana, Mississippi and Alabama disaster areas, thereby authorizing the use of federal money in relief programs. He is expected to visit the region this week, according to White House spokesman Scott McClellan.

    Authorities are making efforts to remove thousands of hurricanerefugees from the Superdome stadium and other shelters in New Orleans, most of which was flooded when sections of its protective levee system collapsed overnight and water from Lake Pontchartrain flooded the streets.

    "The devastation is greater than our worst fears," said Louisiana state Governor Kathleen Blanco. "It is just totally overwhelming."

    "The roads are flooded, the power is out, the phones are down and there is no food or water, and many trees are down," Blanco told reporters in the state capital Baton Rouge.

    The magnitude of the storm's destructive power was felt in equal measure along the shoreline of neighbouring Mississippi, where glitzy casinos, plush homes and shrimp fishing businesses lay in ruins.

    In the Mississippi coastal city of Biloxi, hundreds may have died after being trapped in their homes when a 9-metre storm surge came ashore, a city spokesman said.

    The US military planned to use helicopters to drop giant sandbags filled with gravel into the breach created when the levees surrounding the city of New Orleans gave way. Authorities were also considering plugging the gap with shipping containers filled with sand.

    The economic cost of the hurricane's devastating blow could be the highest in US history, as much as 26 billion US dollars, according to risk analysts' estimates.

    More than 1 million residents in several southeastern states were without electricity, and authorities warned that hundreds of thousands of evacuees were not able to return home.

    "This is one of the most devastating storms in our nation's history," Bush's spokesman Scott McClellan told reporters. "The devastation is enormous. The destruction and loss of life is very sobering."

    In brief remarks during a visit to a California military base, Bush asked Americans to donate for Katrina's victims.

    Federal emergency officials began delivering millions of food rations, drinking water and relief supplies to those stranded by the storm. The American Red Cross announced it was launching its largest mobilization in history for a single natural disaster.

    US crude prices have surged because Katrina shut down oil production in the Gulf of Mexico at a time when gasoline prices had already reached record highs. Enditem