Hurricane Charley, a far bigger and more erratic storm than expected, slashed into Florida's crowded Gulf Coast on Friday with 145-mph winds that peeled off rooftops, wrenched trees from the ground and lifted sea crests to frightening levels.

The fickle storm -- dubbed a "Friday the 13th nightmare" by some residents -- startled emergency officials in the afternoon by suddenly spiking into a Category 4 hurricane over warm Caribbean waters. The storm then made a sharp, unexpected turn to the east and slammed into a string of beach towns near Fort Myers, tossing boats out of the water and shearing telephone poles.

"This is the nightmare scenario we've been talking about for years," Max Mayfield, director of the National Hurricane Center in Miami, told reporters.

While the storm was still spinning across Florida toward Orlando, Gov. Jeb Bush (R) estimated that the total damage could reach $15 billion. The Kennedy Space Center and the Orlando theme parks closed early. Navy ships in Jacksonville were sent out to sea to avoid the storm. President Bush, the governor's brother, declared the state a federal disaster area, freeing up aid money for the four hardest-hit counties: Sarasota, Charlotte, Lee and Manatee.

"Trees are down everywhere," said Kara Winton of the police department in Fort Myers Beach, one of the first places to be hit. "The rain was horizontal. It was quite impressive -- quite scary."

More than 500,000 people were without power late Friday in Florida, and the number was expected to grow. Concerns about flash-flooding were widespread as storm surges peaked at about 14 feet.

At least four people were killed as the storm passed through the Caribbean -- three in Cuba and one in Jamaica. The State Department announced that $50,000 in U.S. assistance will be provided for Cuban storm victims. Three deaths were reported in Florida, including that of a man crushed by a falling tree when he stepped out into the storm to smoke a cigarette.

About 50 people in Punta Gorda, near where the hurricane made landfall, went to Charlotte Regional Medical Center with storm injuries, the Associated Press reported. Josh Putter, the hospital's chief executive, told AP: "There's a lot of crush injuries. Things have fallen on people, crushed their legs, crushed their pelvis -- a lot of bleeding, a lot of major and minor lacerations."

The hospital was so badly damaged that those injured and existing patients were transferred to other hospitals via Coast Guard helicopters.

Charley's ultimate legacy may be its maddening unpredictability. Some local officials complained that they did not receive high-quality information from state and federal officials.

Such criticisms drew an immediate response from state emergency coordinators, who said forecasts were always accompanied by warnings that the track and intensity of the storm might change.

Charley had been projected as a Category 2 hurricane -- with winds topping out at 110 mph. Forecasts showed the storm making a direct hit on the heavily populated Tampa Bay region, where emergency officials responded by ordering the evacuation of nearly 1 million people -- half the state evacuation total and a record for the region.

But sometime around 2 p.m., emergency coordinators in the Lee County town of Cape Coral -- more than 100 miles to the south -- noticed a disturbing blip on their screens.

"Initially, it looked like a wobble," said Pat O'Rourke, a Lee County economic development officer who worked in the emergency operations center. "It eventually turned out to be a turn."

Rather than track toward Tampa, the intensifying storm -- now a Category 4 monster with 145-mph winds -- cranked to the east and blasted toward the low-lying barrier islands off Fort Myers.

"It was like a tight, high-wind doughnut," O'Rourke said.

The unanticipated change of course rousted hundreds -- perhaps thousands -- of people in the Fort Myers area, who had thought the storm would swing around them on the way to Tampa.

About 9,000 people eventually took refuge in Lee County shelters. Few of those are believed to have come from Sanibel Island, a wealthy and isolated enclave off Fort Myers, where at least 100 people doggedly refused to heed three days of evacuation warnings. The island took one of the first hits from the storm, and emergency officials were anxiously awaiting daylight to find out whether any of the holdouts were injured.

The storm's remarkable strength held up as it left the Gulf Coast and ripped across the belly of Florida, maintaining Category 2 110-mph winds and moving northeast at a relatively quick 23 mph.