Irma approaching Tampa Bay area with hurricane-force winds; 5 dead, 3.5M without power The storm is a Category 2 hurricane as it heads north.

 -- Hurricane Irma is barreling up the Sunshine State, bringing heavy rainfall and powerful winds. The deadly hurricane, which is now a Category 2 storm with sustained winds of 100 miles per hour, was moving east of the Tampa metro area.

ABC News has confirmed a fifth storm-related fatality early Monday morning after a person was found dead in a home in Shark Key on Sunday. Monroe County, which includes the Florida Keys, has reported two deaths. Hardee County has also reported two deaths so far and one person died in a single-vehicle crash in Orange County. At least 27 people were killed in the Caribbean.

Millions of Floridians are under orders to evacuate, and many are desperately seeking shelter from the storm. One Naples resident told ABC News she was turned away from two shelters before she and her 10-year-old son were finally accepted at one.

Some 3.5 million Floridians were without power on Sunday.

"We have a dog and there were not that many shelters that accepted dogs," she said, adding, "We didn't want to be that far away from our home." While she and her son stay inside the shelter, her husband is hunkering down with their dog at home.

Irma made its second landfall on Marco Island along the southwest Florida coast this afternoon with 115 mph winds after battering the Florida Keys earlier today.

Beyond the winds and rain that Irma is bringing, the storm surge is also expected to be devastating -- in Naples, waters rose four feet in just 30 minutes.

How Key West and Miami fared

The Florida Keys were hit hard with wind gusts of 120 mph in parts and 89 mph winds in Key West.

Officials in the Florida Keys said that residents who evacuated should not return until further notice.

From there, the storm lashed Miami with winds whipping around high-rise buildings at speeds approaching 100 mph, the National Weather Service said. Two cranes collapsed in the city and a 94 mph wind gust was recorded at Miami International Airport.

Along with the strong gusts of wind, water rushed through Miami's streets. One resident said streets were flooded up to the newspaper stands and the winds were so powerful that windows cracked from the sheer force of the gusts.

The CEO of Miami International Airport said the airport "sustained significant water damage" with wind gusts of nearly 100 mph.

One source of concern before the storm was how the numerous construction cranes in Miami and neighboring cities would fare in the high winds.

The Associated Press is reporting that three cranes have collapsed as of Sunday night: two in Miami and one in Fort Lauderdale.

Naples pelted with wind and rain

Visibility became poor in Naples this afternoon as the eye of the storm neared.

Some now sheltered in Naples had fled from the eastern side of Florida after it was first forecast that Irma would hit the eastern coastline. The mayor of Naples said those in hotels around the city were ordered out of common areas and into their rooms.

After the bulk of the storm passed over the city, Naples officials said that the city's water distribution lines have been broken so residents are being told to boil the water that is coming out of taps.

Florida Gov. Rick Scott warned residents of dangerous storm surges that could reach 10 to 15 feet above sea level in the Naples area.

"Do not think the storm is over when the wind slows down," Scott said Saturday. The dangerous storm surge "will rush in and could kill you."

There have already been four deaths reported in Florida, including a man in Monroe County, which encompasses Key West. He was killed after he lost control of a truck that carried a generator as winds whipped at tropical-storm strength, officials said.

Two other people, a sheriff's deputy and a corrections officer, died from a two-car crash in the rain in Hardee County, which is about 60 miles inland from Sarasota, officials said.

The fourth fatality was reported in Orange County, which is near Orlando, after a car crash that was deemed related to the hurricane.

The deputy, identified as Julie Bridges, was a 13-year veteran of the county force, said Hardee County Sheriff Arnold Lanier. She was heading home after a night shift, the Florida Highway Patrol said. The second victim was a sergeant at the Hardee Correctional Institute who had been on his way to work, the highway patrol said.

Tampa's mayor issues stern warning

Tampa, which is now experiencing wind gusts of over 50 mph, is in the predicted path of the storm, and the city's mayor Bob Buckhorn did not mince words when he warned residents on Twitter earlier today.

"We are about to get punched in the face by this storm. We need to be prepared," he wrote.

He later spoke to ABC News and said that Tampa, which is naturally low-lying and on the Gulf Coast, has taken precautions to prepare.

"I think we're about as ready as any city could be, given what we're about to face," Buckhorn said to ABC News.

He said that the city will deal with the aftermath but "right now, we're pretty much in God's hands."

Millions ordered to evacuate

As the monster storm neared, about 6.5 million Floridians were under mandatory and voluntarily evacuation orders. Evacuations were ordered in Georgia and South Carolina as well.

Over 116,000 people are in 530 shelters across Florida to ride out the storm. 30,000 people are in shelters in Miami-Dade alone.

But others decided to hunker down at home bracing for Irma's impact.

Sylvia Constantinidis, a 27-year resident of Miami, told ABC News earlier this week that she would stay in the city during the storm.

"I own my house. You leave and then there is a major disaster then they don't let you come back to Florida until many days after," Constantinidis said. "If you have any damage or water getting into your house and you have to wait for two or three weeks to come back, then your house will be completely damaged by the time you come back to Florida."

Lost power and reported tornadoes

Roughly 3.5 million customers were without power in Florida late Sunday night, according to Rob Gould, the vice president of communications at Florida Power & Light.

Meanwhile, a tornado watch is in effect today for Fort Myers, Tampa, Melbourne, Daytona Beach and Jacksonville. There have been at least three reported tornadoes in central and south Florida.

Irma's heavy rains and winds are expected to reach Georgia, too, and Georgia Gov. Nathan Deal today expanded his emergency declaration so all Georgia counties are under states of emergency.

ABC News' Daniel Manzo, Erin Dooley, Jordyn Phelps, Will Gretsky, Dominick Proto, Matthew Fuhrman and Chris Donato contributed to this report.