North Carolina corrections officials said more than 3,000 people were relocated from adult prisons and juvenile centers in the path of Florence, and more than 300 county prisoners were transferred to state facilities.
At least 188,000 people were without power in North Carolina and SC early on Friday.
"It's an uninvited brute who doesn't want to leave", said North Carolina Gov. Roy Cooper.
And about 46 miles farther up the waterfront, in New Bern, about 150 people were waiting to be rescued from floods on the Neuse River, WXII-TV reported.
More than 60 people, including many children, were evacuated from a hotel in Jacksonville, North Carolina, after strong winds collapsed part of the roof.
Hurricane Florence has weakened somewhat early Thursday as its outer bands approach the North Carolina coast, but weather officials cautioned that the storm will still bring life-threatening conditions. Significant weakening was expected over the weekend.
Meanwhile more than 630,000 homes and businesses were left without power by Friday afternoon.
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Florence has barreled into the Carolina coast and moved inland, knocking down trees, overflowing rivers, dumping sheets of rain and leading to the deaths of five people before it was downgraded to a tropical storm still capable of wreaking havoc.
According to poweroutage.us, more than 500,000 customers in North Carolina and 50,000 in SC were without power on Friday morning, though the Weather Channel estimates up to 3 million customers could lose power in the Carolinas due to Florence.
Florence was expected to make landfall near Cape Fear, North Carolina, at midday, and forecasters said its size meant it could batter the U.S. East Coast with hurricane-force winds for almost a full day.
Richmond, Va. -based Dominion Energy, which provides power in the northeastern corner of North Carolina, was reporting over 1,900 scattered outages.
Michael Nelson floats in a boat made from a metal tub and fishing floats after the Neuse River went over its banks and flooded his street during Hurricane Florence September 13, 2018 in New Bern, North Carolina.
"Since the track is slower and the storm will reside in the area for a longer period of time rainfall amounts are expected to be extreme", Reid Hawkins, science officer for the National Weather Service office in Wilmington, said in a statement. Hundreds of thousands of people have evacuated the coast, more than 1500 United States flights have been cancelled, factories were shut and farmers rushed to save crops, poultry and pigs in anticipation of the storm. The highest numbers are being reported in New Hanover County. The National Hurricane Center in Miami says more than 16 inches of rain have fallen at locations in southeast North Carolina and another 20 to 25 inches is on the way.
"I feel like the dumbest human being who ever walked the face of the earth", he said.