Hurricane Hermine has hit the Florida Gulf coast with winds of up to 80mph and heavy rains causing flooding and leaving tens of thousands of homes in the dark.
The US National Hurricane Center said Hermine made landfall over northwest Florida, east of St Marks, at 1,30am (EDT).
Within an hour, 70,000 homes in the state capital Tallahassee and thousands more along the coast were without power, with areas also reporting five inches of rainfall.
"It is a mess... we have high water in numerous places," Virgil Sandlin, the police chief in Cedar Key, Florida, told the Weather Channel.
"I was here in 1985 for Hurricane Elena and I don't recall anything this bad."
It is the first hurricane to directly hit the Sunshine State in more than a decade.
It is feared the hurricane, the fourth of the 2016 Atlantic season, could eventually pack wind speeds of up to 95mph.
Storm surges of up to 12ft are threatening the coastline with up to 20 inches of rainfall predicted with the danger of flooding, the forecasters said.
Hurricane warnings play on the TV as shoppers stock up in Saint Marks, Florida
Florida's governor Rick Scott has warned the hurricane is potentially 'life-threatening' and is urging Gulf Coast residents to take precautions immediately.
The warning covers an area from Marineland in Florida to South Santee River in South Carolina.
A hurricane warning was already in effect for a section of Florida's Gulf coast from the Suwanne River to Mexico Beach, and tropical storm warnings in effect for other sections of the coastline.
Tornado warnings for communities throughout northern Florida have also been issued and a tropical storm watch extended to Sandy Hook, New Jersey.
North Carolina's governor Pat McCrory has also declared a state of emergency in the eastern part of the state.
Hermine is expected to drop back down to a tropical storm before pushing into Georgia, the Carolinas and up the East Coast - but still carrying with it the threat of heavy rain and flooding.
