"The fact is this storm is deadly and we know we are days away from an ending", Gov Cooper said. Dozens more were rescued from a collapsed motel.
Screaming winds bent trees toward the ground and raindrops flew sideways as Florence's leading edge moved in for an extended stay along the coast.
The dead included a mother and baby killed when a tree fell on a house in Wilmington, North Carolina.
USA media later said a man in Lenoir County died after heavy winds knocked him down as he tried to check on his dogs.
Storm surges - the bulge of ocean water pushed ashore by the hurricane - were as high as 10 feet, backing up onto rivers already swollen by almost two feet of rain.
Shaken after seeing waves crashing on the Neuse River just outside his house in New Bern, restaurant owner and hurricane veteran Tom Ballance wished he had evacuated.
At 11am yesterday, the hurricane centre said Florence had maximum sustained winds near 75kph and continued to produce catastrophic flooding in the Carolinas. It came ashore along a mostly boarded-up, emptied-out stretch of coastline.
"This system is unloading epic amounts of rainfall, in some places measured in feet and not inches", North Carolina Governor Roy Cooper said on Saturday. Mike Doll, Senior Meteorologist at Accuweather said the winds will continue to slow down over the weekend and the main problem moving forward will be flooding due to heavy rains. But it was clear that this was really about the water, not the wind.
The surges will be most harmful in North Carolina, with rain and flooding also making the dangerously high water levels even worse. With Florence, it'll be the same amount of rainfall in three days. North Myrtle Beach, South Carolina, had around 7 inches (18 centimeters).
People around the Carolinas are being told that say they can buy flood insurance policy right now that will cover damage done by Florence, according to FEMA.
About 9,700 National Guard troops and civilians have been deployed, with high-water vehicles, helicopters, and boats.
That's about 220 miles from Wrightsville Beach, North Carolina, where Florence made landfall as a Category 1 hurricane at 7:15 a.m. September 14, coming ashore along a mostly boarded-up, emptied-out stretch of coastline.
Authorities warned, too, of the threat of mudslides and the risk of an environmental disaster from floodwaters washing over industrial waste sites and hog farms.
It's moving very slowly, at about 2mph (3.2km/h). Then it will swing to the northeast in the middle of next week on a path to the Atlantic Ocean near Nova Scotia, where it will be an extratropical low with gale-force winds.
Non-profit groups are preparing to serve tens of thousands of meals daily in the most-damaged areas, while state and federal emergency officials are locating temporary housing, including hotel rooms, for storm victims in the weeks or months that they're displaced.
The Neuse is expected to crest at more than nine feet (3 meters) above flood stage Monday and Sheehan said the company expects the same ash basins are likely to be inundated again.
"WE ARE COMING TO GET YOU", the city tweeted around 2 a.m. "You may need to move up to the second story, or to your attic, but WE ARE COMING TO GET YOU".
Boat teams including volunteers rescued some 360 residents, including Sadie Marie Holt, 67, who first tried to row out of her neighbourhood during Florence's assault. "We have two boats and all our worldly possessions", said Susan Patchkofsky, who refused her family's pleas to evacuate and stayed at Emerald Isle with her husband.