Hurricane Ike, a colossal storm nearly as big as Texas itself, is battering the coast.

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At about 600 miles across, the hurricane is a monster.

Towering waves have been crashing over the 17-foot-high Galveston seawall, and floodwaters are rising in low-lying areas.

The storm is threatening to give Houston its worst pounding in a generation.

But even as Ike bears down, it's become clear that many of the 1 million coastal residents who had been ordered to get out refused to do so and are taking their chances.

Before sunset, power had been knocked out to hundreds of thousands of customers in Louisiana and along the Texas coast. That number is expected to climb.

As of 9 p.m. Eastern time, Ike was centered about 70 miles southeast of Galveston, moving at 13 mph. It's close to a Category 3 storm with winds of 110 mph, and is expected to strengthen by the time the eye hits land.

Forecasters said Ike's storm surge -- not high winds -- will be the deadliest aspect of the storm. The National Hurricane Center is forecasting a 20-foot surge for a large swath of Texas and the Louisiana coasts. Meteorologist Dennis Feltgen said some waves could be 50 feet tall.

Experts said Ike is about 70 percent larger than the average hurricane, and a 15- to 22-foot storm surge is expected wherever Ike makes landfall.

Parts Of Houston Under Curfew As Ike Nears

Parts of Houston and surrounding areas have been put under a curfew order as Hurricane Ike approaches.

Mayor Bill White and Harris County Judge Ed Emmett enacted the curfew Friday evening in areas that are already under a mandatory evacuation.

Officials said police would punish violators who are on the streets between 7 p.m. and 6 a.m.

Evacuations Ordered But Some Stay Behind

Nearly 1 million people have been ordered to evacuate ahead of the storm.

However, authorities said tens of thousands have ignored evacuation orders and are staying behind.

An Associated Press survey shows that in three counties alone, some 90,000 people have chosen not to leave despite dire warnings from forecasters.

The emergency management coordinator for Galveston County estimated that 80 percent of the residents evacuated. That leaves more than 11,000 residents in the county that is expected to take a direct hit from Ike's massive storm surge.

Farther up the coast, officials said half the residents of Beaumont stayed put less than two weeks after many evacuated for Hurricane Gustav, only to see the storm miss the city entirely.

In Houston, the fourth-largest U.S. city, officials are telling people who decide to stay to hunker down.

Residents who decide to stay are being told to board up windows and stock up on drinking water and nonperishable food.

Hardware stores have put limits on the number of gas containers that people can buy. Batteries, drinking water and other storm supplies are running low, and grocery stores are getting set to close.

Perry Asks For Emergency Aid

Texas Gov. Rick Perry is asking Bush for a "wide-reaching emergency declaration" in all 88 counties in the line of fire from Hurricane Ike.

Perry said a declaration would ensure 100 percent reimbursement for all storm-related costs.

The Federal Emergency Management Agency already has teams ready to respond in Texas and has water and food ready to distribute after the storm.

Chertoff said more than 100,000 homes will be affected by flooding and millions of people will be without power after the storm. Already, some homes are in the dark in Galveston, where the storm is set to come ashore.