After an excruciatingly sluggish journey to the U.S. mainland, Hurricane Wilma (search) slammed into southwest Florida early Monday, bringing blinding rains and howling 125-mph winds that whipped trees, road signs and other debris into the air.

About 6 million residents lost power and at least six people were killed in Florida, bringing the death toll from the storm's march through the tropics to 25.

"It's very, very dangerous right now" in the county, Fowler told FOX News on Monday. He advised people to stay inside.

"There's extensive damage in terms of trees down, power lines down, public buildings that have been damaged and heavy damage to private residences," Fowler added. "Overall, we're looking at a very serious situation here."

• Click here to track Hurricane Wilma.

Three Florida counties were declared disaster areas, the acting director of the Federal Emergency Management Agency (search) said in an afternoon press conference. David Paulison predicted that number would grow.

Wilma also killed at least six people in Mexico and 13 others in Jamaica and Haiti as it made its way across the Caribbean last week.

After a slow, weeklong journey that saw it pound Mexico's Yucatan Peninsula for two days, Wilma made a mercifully swift seven-hour dash across lower Florida, from its southwestern corner to heavily populated Miami, Fort Lauderdale and West Palm Beach on the Atlantic coast.

As it moved across Florida, Wilma weakened to a Category 2 storm with winds of 105 mph. But it was still powerful enough to flatten trees, break water mains, litter the streets with billboards, turn debris into missiles and light up the sky with the blue-green flash of popping power transformers.

Officials said it was the most damaging storm to hit the Fort Lauderdale since 1950.

The storm's reach was so great that it left homes and businesses without power as far north as Daytona Beach, an eight-hour drive north from Key West. A tornado spun off by the storm damaged an apartment complex near Melbourne on the east coast, 200 miles from where Wilma came ashore.

More than one-third of the state's residents lost power. Florida Power & Light, the state's biggest utility, said it could take weeks to restore electricity to everyone.

By early afternoon, Wilma had swirled out into the open Atlantic, back up to 115-mph Category 3 strength but on a course unlikely to have much effect on the East Coast. Forecasters said it would stay well offshore.

The insurance industry estimated the insured losses in Florida at anywhere from $2 billion to $9 billion.

"We have been huddled in the living room trying to stay away from the windows. It got pretty violent there for a while," said Eddie Kenny, 25, who was at his parents' home in Plantation near Fort Lauderdale with his wife. "We have trees down all over the place and two fences have been totally demolished, crushed, gone."

The 21st storm of the 2005 season — and the eighth hurricane to hit Florida in 15 months — howled ashore around daybreak just south of Marco Island as a Category 3, cutting electricity to the entire Florida Keys. A tidal surge of up to 9 feet swamped parts of Key West in chest-high water, and U.S. 1, the only highway to the mainland, was flooded.

"A bunch of us that are the old-time Key Westers are kind of waking up this morning, going, 'Well, maybe I should have paid a little more attention,"' said restaurant owner Amy Culver-Aversa, among the 90 percent of Key West residents who chose to ignore the fourth mandatory evacuation order this year.

Wilma brought 8 inches of rain to Miami-Dade County, nearly 61/2 to Naples and 3 to Fort Lauderdale. The flooding could well have been worse if the storm had lingered over the state instead of racing straight through, National Hurricane Center meteorologist Mark McInerney said.

"There's really no good scenario for a hurricane. Just a lesser of two evils," he said.

In Cuba, rescuers used scuba gear, inflatable rafts and amphibious vehicles to pull nearly 250 people from their flooded homes in Havana after Wilma sent huge waves crashing into the capital city and swamped neighborhoods up to four blocks inland with 3 feet of water.

In Cancun, Mexico, troops and federal police moved in to control looting at stores and shopping centers ripped open by the hurricane, and hunger and frustration mounted among Mexicans and stranded tourists. President Vicente Fox announced plans to start evacuating some 30,000 frazzled tourists.

Wilma, part of the busiest Atlantic hurricane season on record, came ashore in Florida at 6:30 a.m. EDT near Cape Romano, 22 miles south of Naples, spinning off tornadoes and bringing a potential for up to 10 inches of rain, the National Hurricane Center said.

The hurricane is expected to race up the Atlantic Seaboard and reach the coast of Canada by early Wednesday. But forecasters said it will probably stay so far offshore that it will not even bring heavy rain to the eastern United States.

"Most of the impact on the U.S. will be ending in the next several hours," Ed Rappaport, deputy director of the National Hurricane Center, said around midday.

A gust was clocked at 104 mph at the National Hurricane Center in Miami, causing howling even in the bunker-like building.

In Weston, near Fort Lauderdale, Kim DuBois sat in her darkened house with her two children and husband, with the power out and the storm shutters up. For light they used a battery-powered pumpkin lantern they bought for Halloween.

"I could hear tiles coming off the roof," she said. "There are trees on cars and flooding at the end of our street." She added: "Really what I'm afraid of is tornadoes."

More than 33,000 people were in shelters across the state. But no mandatory evacuations were ordered along Florida's heavily populated east coast. And in the low-lying Florida Keys, not even 10 percent of the Keys' 78,000 hardy, storm-tested residents evacuated, Sheriff Richard Roth said. This was the fourth hurricane evacuation of the Keys this year.

About 35 percent of Key West was flooded, including the airport, said Jay Gewin, an assistant to the island city's mayor.

Key West Police Chief Bill Mauldin said the flooding was severe — "more extensive than we've seen in the past."

Collier County was one of the three counties declared disaster zones. But Jim Von Rinteln of Collier County Emergency Management told FOX News, "We don't appear to have anyone in need of rescue."

Structural damage was largely limited to roof tiles peeled off by the wind, Von Rinteln said.

President Bush, criticized for a slow response to Hurricane Katrina (search), signed a disaster declaration for hurricane-damaged areas and promised swift action to help the victims.

"We have prepositioned food, medicine, communications equipment, urban search-and-rescue teams," he said. "We will work closely with local and state authorities to respond to this hurricane."

National Guard units airlifted 12 patients from a Key West hospital, and other units were prepared to deliver food, water and other supplies to the Keys.

State and federal officials had trucks of ice and food ready. FEMA was prepared to send in dozens of military helicopters and 13.2 million ready-to-eat meals.

A man in the Fort Lauderdale suburb of Coral Springs died when a tree fell on him. Another man in rural Collier County died when his roof collapsed on him or a tree fell on his roof. In Palm Beach County, a man went to move his van and was killed when debris smashed him into the windshield.

Also, an 83-year-old St. Johns County woman died in a weekend car crash while evacuating. A man in Collier County had a fatal heart attack while walking in the storm. An 82-year-old woman in Boyton Beach died after a sliding glass door in her living room fell on her as she looked out.

Weary forecasters also monitored Tropical Depression Alpha, which became the record-breaking 22nd named storm of the 2005 Atlantic season. Alpha, which drenched Haiti and the Dominican Republic on Sunday, was not considered a threat to the United States.

A tornado touched down Monday in Brevard County, damaging an apartment complex. No one was injured. Wilma's arrival also was announced by at least four tornadoes Sunday night — including one near Kennedy Space Center at Cape Canaveral — that damaged some businesses but caused no injuries.

Elaine Kelley, a 43-year-old waitress, was staying in her daughter's condo near the water in Everglades City, a village of about 700 people on the southwest coast. After wading through thigh-deep water to get to a nearby hotel, she said she wouldn't make the mistake of staying through a hurricane again.

"I'll never go through another one," a wet and shivering Kelley said. "I didn't expect anything like this. I was watching roofs blow off all over the place."

The storm impressed even amateur hurricane chaser Josh Morgerman. A marketing executive from Los Angeles, Morgerman flew to Tampa on Saturday to meet the storm, left Naples as the eye passed and drove to Everglades City.

"It was very serene and there were birds flying," a wet and shivering Morgerman said. "And then when we got here and got out of the car, it was like a rocket went off."

Wilma's arrival in Florida came five days after it astounded forecasters with terrifying Category 5 winds of 175 mph. At one point, it was the most intense storm — as measured by internal barometric pressure — on record in the Atlantic basin.

For a change, lack of air conditioning was not an immediate concern in the aftermath of a hurricane. The strong cold front that pushed Wilma through Florida was expected to send the wind-chill factor into the 40s Tuesday morning.

The Associated Press contributed to this report.