(CNN) -- Hurricane Irma hit northern Cuba during its long, destructive march toward Florida, where it's expected to hammer the state with whistling winds, heavy rain, and surging seas.
Florida authorities went door-to-door warning residents of the massive hurricane, sending crowds jamming highways as they fled north.
The powerful Category 5 storm had maximum sustained winds of 160 mph when it made landfall on Cuba's Camaguey Archipelago, the National Hurricane Center said late Friday.
It edged closer to South Florida after killing 24 people in the Caribbean this week and strengthened to a Category 5 storm in Cuba. Hours earlier Friday, it was a Category 4.
Irma is expected to be near the Florida Keys and South Florida by early Sunday, and many residents there have moved inland. About 5.6 million people in the state have been ordered to evacuate, Gov. Rick Scott said.
"If you have been ordered to evacuate, leave now. Not tonight, not in an hour, now," Scott said Friday night. Staying in homes could subject residents to storm surge as high as 12 feet, the governor added.