Early on Friday, South Carolina emergency officials said there was still time, "but not a lot of time" for people to leave flood-prone areas.
Though Florence's shrieking winds diminished from hurricane force as it came ashore, forecasters said the sheer size of the 350-mile-wide storm and its painfully slow progress across North and SC in the coming days could leave much of the region under water.
After coming ashore in North Carolina as a Category 1 hurricane, Florence was downgraded to a tropical storm Friday afternoon and trudged into SC as night came. The storm has since been downgraded to a tropical storm.
"We know we're in for a long haul here", Cooper said of predictions that the storm will linger over the area. Hurricane-force winds were extending out up to 80 miles from the center, and tropical-storm-force winds extended up to 195 miles, the center said.
Coastal streets flowed with ocean water, and more than 460,000 homes and businesses were without power, mostly in North Carolina, according to poweroutage.us, which tracks the nation's electrical grid. More than 60 people had to be rescued in another town as a cinderblock motel collapsed at the height of the storm's fury.
Florence flattened trees, buckled buildings and crumpled roads.
About 10 million people could be affected by the storm and more than 1 million were ordered to evacuate the coasts of the Carolinas and Virginia.
A mother and baby were killed when a tree fell on their home in Wilmington, North Carolina, sending the child's father to the hospital. Another man in the county who was checking on his dogs outside was killed in what his family thought was a wind-related death Friday morning, emergency officials said.
A gust of 169km/h was recorded at Wilmington airport, surpassing the power of Hurricane Fran two decades ago.
Warning over needles in strawberries
Police have urged consumers who have bought an affected punnet to take it to police for forensic examination. The association said it could be a disgruntled former farmer who's putting the needles in the strawberries.
"I couldn't even imagine", he said.
At 5 a.m. EST Saturday, the center of the storm was about 35 miles west of Myrtle Beach, South Carolina, with maximum sustained winds at 50 mph. It came ashore along a mostly boarded-up, emptied-out stretch of coastline.
At 5 p.m., Florence had been downgraded to a tropical storm, with sustained winds of 70 miles per hour.
Rainfall is already being measured in feet in parts of North Carolina, and there is more to come.
"Gradual weakening is forecast while Florence moves farther inland during the next couple of days, and it is expected to weaken to a tropical depression by tonight".
WILMINGTON, NC - SEPTEMBER 14: Firefighters look into a home that a large tree fell on that has three people trapped after Hurricane Florence hit the area on September 14, 2018 in Wilmington, North Carolina.
At least five people, including a mother and her infant, have died in North Carolina as Tropical Storm Florence slowly moved from the Tar Heel State into SC, officials said Friday.
About 9,700 National Guard troops and civilians have been deployed, with high-water vehicles, helicopters and boats.
Florence's eyewall reached shore near Wilmington, N.C., just before 6 a.m. ET Friday; more than an hour later, the National Hurricane Center announced, it had "finally" made landfall near Wrightsville Beach.
Florence is expected to turn west and then north moving through the Carolinas and the Ohio Valley by Monday, the hurricane centre said. That's enough to fill the Chesapeake Bay or cover the entire state of Texas with almost 10 centimetres of water, he calculated.