Florence is expected to crawl to the west - battering everything in its path with 80mph winds - before smashing into neighbouring SC.
In Myrtle Beach, rescuers discovered a dead mother and her baby, two of at least five deaths blamed on the storm, after spending much of the day trying to cut through debris and a towering tree that crashed through their roof. The father sustained injuries and was transported to New Hanover Regional Medical Center in Wilmington for medical care.
Nearly two million people have been displaced by Florence (Pic: GETTY) "It wasn't safe".
"We knew this was going to be a big storm, but it is going to be of epic proportions", North Carolina Governor Roy Cooper told a news conference in Raleigh.
Officials said several agencies responded to the incident.
Florence had been a Category 3 hurricane with 120-mph winds on Thursday, but dropped to Category 1 before coming ashore. But the National Hurricane Center warned people of the hurricane's strong winds and its "life-threatening storm surge and rainfall" in an update Thursday evening.
To the south, storm surge pushed water levels at Johnny Mercer Pier at Wrightsville Beach, where Florence made landfall at 7:15 a.m. with 90 miles per hour winds, to more than 8.5 feet.
By Friday evening, the centre of the storm had moved to eastern SC, with maximum sustained winds of 70 miles per hour.
Restoring power to all customers could take weeks, it said. Emergency declarations were in force in Georgia, South and North Carolina, Virginia, Maryland and the District of Columbia. "You may need to move up to the second story, or to your attic, but WE ARE COMING TO GET YOU", the authorities in New Bern said on Twitter.
After reaching a terrifying Category 4 peak of 225 km/h earlier in the week, Florence made landfall as a Category 1 hurricane at 7:15 a.m.at Wrightsville Beach, a few kilometres east of Wilmington and not far from the SC line.
More than 600,000 people had already lost power by 1 p.m. Friday, the North Carolina Department of Public Safety reported.
In Jacksonville, North Carolina, next to Camp Lejeune, firefighters and police fought wind and rain as they went door-to-door to pull people out of the Triangle Motor Inn after the structure began to crumble and the roof started to collapse.
The storm surge, water pushed by a storm over land that would normally be dry, "overwhelmed" the town of New Bern at the confluence of the Neuse and Trent rivers, Cooper said.