MIAMI, Fla. - 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.

The storm has killed 37 people in the Caribbean and at least seven people in the U.S., and it's left nearly 6 million Florida customers without power.

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.