Authorities fear the death toll will go higher as the tropical storm crawls westwards across SC.
Florence flattened trees, buckled buildings and crumpled roads.
The hurricane centre said the storm will eventually break up over the southern Appalachians and make a sharp rightward swing to the northeast, its rainy remnants moving into the mid-Atlantic states and New England by the middle of next week. The storm knocked out power to almost 930,000 homes and businesses, and the number could keep rising.
In New Bern, at the confluence of the Neuse and Trent rivers in North Carolina, the storm surge overwhelmed the town of 30,000. Rescue crews have used boats to reach hundreds of people trapped by the rising waters. "And we had no belief it would be as significant an event as it was, â€ he said. â€œThis is a 500- or 1,000-year event. â€Eudy´s family has lived in New Bern since the 1850s, he said".
Florence "has been most unpredictable, but what has been predictable and steady is our concern for heavy rain and flooding", South Carolina Gov. Henry McMaster (R) said, according to the Charleston Post and Courier.
Protected: More than 20,000 people in shelters in North Carolina, 6,400 in SC and 400 in Virginia.
The doors of many homes suffered so much wind damage they appeared to have been kicked in, while the city's beloved fiber-glass bear statues, which are sponsored by local businesses, were floating down streets.
A mother and her child were killed in Wilmington when a tree fell on their home on Friday.
The warmer air and water also makes storms more intense or stronger, Stott said. In the state´s Pender County, a woman died of a heart attack; paramedics trying to reach her were blocked by debris. She said that when tourists start returning Sunday morning, she's not sure they'll find what they need. But the hurricane had slowed to a crawl as it traced the North Carolina-South Carolina shoreline, drenching coastal communities for hours on end.
The storm's center is crawling inland over SC, but many of its main rain bands still are over already-saturated North Carolina - setting up what may be days of flooding for some communities.
The White House said President Donald Trump would visit hurricane-hit areas next week "once it is determined his travel will not disrupt any rescue or recovery efforts". These two were rescued overnight from a hotel that took major storm damage. They are part of Cajun Navy which is an informal volunteer group set up after Hurricane Katrina.
It was downgraded to Category 1 before coming ashore on Friday near Wrightsville Beach close to Wilmington, North Carolina.
The worst is likely yet to come for places such as Conway, South Carolina, about 15 miles inland from Myrtle Beach.
Christy Hall, South Carolina's state secretary of transportation, on Saturday announced plans to build two emergency dams as rainfall is expected to flood routes leading into Horry County, where Myrtle Beach is located.