* Category 4 Irma passes over Florida Keys, heads to mainland
* At least 1.4 million homes, businesses without power
* First U.S. death linked to storm
FORT MYERS/MIAMI Sept 10 (Reuters) - Packing 130-mph (210-kph) winds, Hurricane Irma knocked out electricity to more than 1 million Florida homes and businesses on Sunday as it headed towards the state's Gulf Coast, threatening potentially catastrophic flooding.
After wreaking havoc in the Caribbean, the deadly storm was located about 80 miles (125 km) south-southeast of Naples on a course for the state's western coast. Storm surges - water driven ashore by the winds - of up to 15 feet (4.6 m) were possible, according to the National Hurricane Center.
"I am very concerned about the west coast," Florida Governor Rick Scott told "Fox News Sunday." The coastline is home to cities like Tampa and St. Petersburg.
Irma, which prompted one of the largest evacuations in U.S. history, is expected to cause billions of dollars in damage to the third-most-populous U.S. state, a major tourism hub with an economy comprising about 5 percent of U.S. gross domestic product.
At least 1.4 million Florida homes and businesses had lost power as the storm pummeled the southern part of the state, according to Florida Power & Light. FPL said it would have to completely rebuild part of its system, which would take weeks not days.
Irma, at one point one of the most powerful storms ever recorded in the Atlantic, has now passed over the lower Florida Keys on its way to the mainland, with the NHC forecasting that its center eye will move near or over the state's west coast later on Sunday. The extent of the damage Irma caused on the Keys was not immediately clear.
Irma, which killed at least 22 people as it tore through Caribbean islands toward Florida, has already claimed at least one life in the state. Emergency responders in the Florida Keys said they pulled a man's body from his pickup truck, which had crashed into a tree in high winds.
The storm winds downed a construction crane, trees and signs and shook tall buildings in Miami, which was about 100 miles (160 km) from Irma's core.
"We're going to get 100-mile-an hour winds," said Bob Korosec, an 83-year-old retiree who planned to ride out the storm with his wife in their St. Petersburg home. "We picked up all the stuff outside that could be a missile into our house. I just hope it doesn't blow off our roof."
Irma is now a Category 4 storm, the second-highest designation on the Saffir-Simpson scale.
One woman in Miami's Little Haiti neighborhood delivered her own baby, with medical personnel coaching her on the phone because emergency responders were not able to reach her, the city of Miami said on Twitter. The two are now at the hospital, it said.
About 6.5 million people, or about a third of the state's population, had been ordered to evacuate.
But some people decided to ride out the storm in their homes. Midway up the state's Gulf Coast in Clearwater, Sarah Griffin said she planned to hunker down in a closet in her boarded-up concrete house.
"You've just got to have plenty of beer, Captain Morgan, vodka, (and) you'll get through," said Griffin, 52.
The NHC has put out a hurricane warning and a tropical storm warning stretching through almost all of Florida into Georgia and South Carolina, home to more than 20 million people.
Irma comes just days after Hurricane Harvey dumped record-setting rain in Texas, causing unprecedented flooding, killing at least 60 people and leaving an estimated $180 billion in property damage in its wake. Almost three months remain in the Atlantic hurricane season, which runs through November.
(Additional reporting by Sarah Marsh in Remedios, Marc Frank in Havana, Bernie Woodall, Ben Gruber and Andy Sullivan in Miami, Jeff Mason in Washington, Colleen Jenkins in Winston-Salem, North Carolina and Scott DiSavino in New York; Writing by Scott Malone; Editing by Ross Colvin)