Rescuers searched devastated communities for the dead and injured and thousands of people were homeless after Hurricane Charley shredded mobile home parks and damaged tens of thousands of buildings in southwest Florida.
"Our worst fears have come true," said Florida Governor Mr Jeb Bush, who described seeing "entire communities totally flattened."
Charley, the strongest hurricane to hit Florida in 12 years, roared in on Friday with 145 mph (233 kph) winds, striking with more ferocity and farther south than initially forecast and taking many in the area by surprise.
It churned northeast through the state and lashed the Carolinas on Saturday, but as a weaker tropical storm.
State emergency officials said at least five people were killed in the storm, which caused widespread destruction where it first punched in around Punta Gorda, Port Charlotte and Fort Myers.
The toll appeared likely to rise as search crews edged their way through standing water and debris-clogged roads to reach dangerously unstable buildings.
"As of yet they can't get the search and rescue teams out into every possible place in order to quantify the deaths," Governor Bush said.
The Federal Emergency Management Agency estimated 50,000 people were in shelters and 80 percent of the buildings in Charlotte County were damaged. Many mobile homes were reduced to piles of twisted metal and smashed furniture.
Florida sought emergency housing assistance for 10,000 families. Emergency workers were bringing in food, water, cots, blankets and clothes. About 1.3 million people had no power, three cities had no running water, and nighttime curfews were imposed.
National Guard troops, power company workers and search teams streamed in to the area. But emergency services were also ravaged by the storm, complicating rescue efforts.
Six hospitals were damaged or destroyed. Coast Guard helicopters ferried the most seriously injured patients from Charlotte Regional Medical Center to a Tampa hospital.
President George W Bush declared Florida a disaster area to speed emergency aid. The president plans to visit the area today.
Forecasters had expected Charley to hit the Tampa area farther north and nearly 2 million people were told to evacuate. But the hurricane gained strength and made a last-minute turn that brought it ashore farther south, swiping people who had ignored evacuation orders because they thought they would be safe.
Charley was blamed for four deaths in Cuba and one in Jamaica as it swept through the Caribbean earlier in the week.
As a Category 4 storm - the second strongest on a scale used to rate hurricanes - Charley was one of the most dangerous storms to hit Florida. Hurricane Andrew, which hit Miami in August 1992 and caused $25 billion in damage, was a Category 5.