GALVESTON, Texas (AP) — A massive Hurricane Ike sent white waves crashing over a seawall and tossed a disabled 584-foot freighter in rough water as it steamed toward Texas Friday, threatening to devastate coastal towns and batter America’s fourth-largest city.

Ike’s eye was forecast to strike somewhere near Galveston late Friday or early Saturday then head inland for Houston, but the sprawling weather system nearly as big as Texas was already buffeting the Gulf Coast and causing flooding in areas still recovering from Labor Day’s Hurricane Gustav.

Because of its ominous size, storm surge and flooding were the greatest threats. In unusually strong language, forecasters even warned of “certain death” for stalwarts who insisted on staying in Galveston; most had complied, along with hundreds of thousands of fellow Texans in counties up and down the coastline. But in a move designed to avoid highway gridlock as the storm closed in, most of Houston’s 2 million residents hunkered down and were ordered not to leave.

White waves as tall as 15 feet were already crashing over Galveston’s seawall. It was enough to scare away Tony Munoz and his wife, Jennifer, who went down to the water to take pictures, then decided that riding out the storm wasn’t a good idea after all.

“We started seeing water come up on the streets, then we saw this. We just loaded up everything, got the pets, we’re leaving,” Tony Munoz, 33, said. “I’ve been through storms before but this is different.”

Ike’s 105-mph winds and potential 50-foot waves initially stopped the Coast Guard from attempting a risky helicopter rescue of 22 people aboard a 584-foot freighter that broke down in the path of the storm about 90 miles southeast of Galveston, Chief Petty Officer Mike O’Berry said. The ship was hauling petroleum coke used to fuel furnaces at steel plants.

But midday Friday, the Coast Guard changed its mind and decided to stage a rescue. Petty Officer Tom Atkeson said rescue swimmers and Coast Guard and Air Force aircraft were on their way to reach the ship.

Daniel Brown, a forecaster at the National Hurricane Center, said Ike was about 600 miles across, roughly the distance between Houston and Panama City, Fla. “It takes up almost the northern Gulf,” he said.

The National Hurricane Center said tropical storm-force winds of at least 39 mph extended across 550 miles, and hurricane-force winds of at least 74 mph stretched for 240 miles. A typical storm has tropical storm-force winds stretching only 300 miles.

Yet a stubborn few defied orders to leave. Emory Sallie, 44, of Galveston, said he had braved storms in the past and didn’t think Ike would be any different. He didn’t believe the dire warnings — he was more worried about the wind, not the flooding.

“If the island is going to disappear it has to be a tsunami,” he said, as he walked along the block where his home is located, drinking a beer and smoking a cigarette. “If it ain’t your time you ain’t going anywhere.”

In Surfside Beach, a small coastal town of about 805, water was already knee-deep in the streets and skies were growing increasingly dark. Police were going around in a dump truck trying to get holdouts to evacuate while there was still time. The police chief asked one stubborn couple to write their names and Social Security numbers on their forearms in black magic marker “in case something bad were to happen.” They soon changed their minds, and police were wading an aluminum boat through floodwaters to rescue them.

About 60 miles inland in Houston, officials said residents should not flock to the roadways en masse, creating the same kind of gridlock that cost lives — and a little political capital — when Hurricane Rita threatened Houston in 2005. Some evacuation orders were in effect for low-lying sections of the Houston area, but for the most part, people stayed. Large hospitals in the city moved some patients away from windows, but they did not send them away.

Three days before landfall, Rita bloomed into a Category 5 and tracked toward the city. City and Harris County officials told Houstonians to hit the road, even while the population of Galveston Island was still clogging the freeways. The evacuation itself wound up far more dangerous than the storm: 110 people died during the effort, while the eventual Category 4 storm killed nine. Houston ultimately was spared a direct hit as the storm took a last-minute turn to the northeast and landed on the Texas-Louisiana border.

Houstonians streamed in and out of a grocery store near downtown Friday morning, carts filled with last-minute supplies such as water and Wheat Thins. Ken Wilson, 51, cut short a vacation to California to return home and ready for Ike. He loaded eight gallons of water into his car trunk before heading home to ride out the storm with his wife.

Wilson said it was too late for him to board up his house, though he had stocked up on ice and batteries.

“We’ll just tape up to keep things from flying around. I’m apprehensive about how high the winds are going to be, and windows breaking,” he said. “What’s the philosophy? Run from the water, shelter from the wind? If it’s wind: Hunker down.”

Business owners Lisa and Tresa Biggerstaff were busy boarding up their shop, Dacapo’s Pastry Cafe, located in the city’s Heights area.

“We’ll just turn it over to God and let whatever happen, happen,” Tresa Biggerstaff said as she watched her friend, Preston Witt, cut half-inch thick plywood. “We’re not scared at all.”

Texans were getting hit from both sides, as the remnants of Tropical Storm Lowell, a Pacific system, dumped nearly 8 inches of rain on Lubbock in 24 hours, flooding homes and roads. Some businesses closed, and Texas Tech University and other schools canceled Friday classes.

Ike would be the first major hurricane to hit a U.S. metropolitan area since Katrina devastated New Orleans three years ago. For Houston — a city filled with gleaming skyscrapers, the nation’s biggest refinery and NASA’s Johnson Space Center — it would be the first major hurricane since Alicia in August 1983 came ashore on Galveston Island, killing 21 people and causing $2 billion in damage.

Galveston, a barrier island and beach town about 10 feet above sea level, was also the scene of the nation’s deadliest hurricane, the great storm of 1900 that left at least 6,000 dead. But that also was before officials had the ability to warn residents that a hurricane was coming, and before the seawall was built to protect the community.

If the storm stays on its projected path, it could head up the Houston ship channel and through Galveston Bay, which Homeland Security Secretary Michael Chertoff called a nightmare scenario.

At 2 p.m. EDT Friday, the Category 2 storm was centered about 165 miles southeast of Galveston, moving to the west-northwest near 12 mph. Forecasters warned it could become a Category 3 storm with winds of at least 111 mph before the eye strikes land.

Hurricane warnings were in effect over a 400-mile stretch of coastline from south of Corpus Christi to Morgan City, La. Tropical storm warnings extended south almost to the Mexican border and east to the Mississippi-Alabama line, including New Orleans.

The oil and gas industry was closely watching the storm because it was headed straight for the nation’s biggest complex of refineries and petrochemical plants. The upper Texas coast accounts for one-fifth of U.S. refining capacity, and many platforms were shut down. Wholesale gasoline prices jumped to around $4.85 a gallon for fear of vast shortages. That was up substantially from about $3.25 on Wednesday and less than $3 on Tuesday.