Local residents have been warned to remain in shelters as a slightly weakened Hurricane Frances continues to batter Florida's east coast.
The storm is slowly progressing across the state
The hurricane brought a night of powerful winds and torrential rain to the "Sunshine State", with low-lying areas at risk of flooding.
Buildings have been damaged, trees uprooted and up to two million homes are without power.
Many of the area's 2.5 million people are thought to have fled to safety.
Weakened but menacing
The storm, which has already been blamed for the deaths of two people in the Bahamas, weakened at dawn and was downgraded to a category one hurricane.
But Frances is still packing sustained winds of 90mph (144km/h) and up to 12in (30cm) of rain is expected throughout the day.
A wind gust of 124mph (200km/h) was measured at Port Canaveral, near Cape Canaveral.
In Palm Bay, trees were bent and lampposts shook in the howling gusts, the AP news agency reported.
Many people have already spent two days in emergency shelters
Further south in Forth Piece, the storm shredded awnings and streets were blocked by toppled palm trees.
Some evacuees had to leave their shelter, as winds damaged the roof of the school where they had taken refuge.
About 230 miles (370km) of Florida coastline remain under hurricane warning.
Florida Governor Jeb Bush told residents to stay indoors.
"As we all know, some of the loss of life occurs after the storm. There'll be a lot of rain, a lot of utility lines down, a lot of power lines in the water," he said.
Meteorologists warn that Frances could regain intensity as it travelled over the warm water of the north-eastern Gulf of Mexico on Monday.
At 0900 (1300 GMT), the storm was 35 miles (56km) east of Sebring.
It is moving west-northwest at 8mph (12km/h).
Our correspondent was almost swept off his feet
Tornadoes have been sighted among winds swirling to the north, in the second big storm in less than a month.
About 2.5 million people -15% of the population - were ordered to leave coastal areas in trailer parks, in one of the biggest evacuation orders in the state's history.
Governor Bush was due to visit damaged areas later in the day.
His brother, President George W Bush, has declared five Florida counties major disaster zones, but officials say it could be 24 hours before a full and accurate picture of the damage is available.
US meteorologists say the hurricane made landfall near Stuart, about 110 miles (175km) north of Miami, at about 0100 local time (0500 GMT) on Sunday - a day later than forecast.
Reporting from New Smyrna Beach, at the storm's northern edge, the BBC's Daniel Lak could barely stand upright in the driving wind.
An Associated Press correspondent in Stuart reported that transformers popped along streets, sending sparks into darkened skies as Frances slammed in.
The wind-whipped coastal waters resembled a churning hot tub, the reporter added.
As well as the power cuts, water supplies have been hit in some areas.
Damage from the last hurricane in August still has not been cleared up.
Hurricane Charley left at least 26 people dead and caused billions of dollars of damage.