More than 2 feet of rain already had fallen in places, and the drenching went on and on as Florence, a hurricane-turned-tropical storm, practically parked itself over the two states.
With tropical storm-force winds swirling 350 miles wide, Florence continued deluging the Carolinas on Saturday morning after pushing surging seas far ashore.
In the city of New Bern near the North Carolina coast, the storm surge overwhelmed the town of 30,000, which is at the confluence of the Neuse and Trent rivers.
And on Saturday evening, Duke Energy said heavy rains caused a slope to collapse at a coal ash landfill at a closed power station outside Wilmington, North Carolina.
Police in Wilmington, North Carolina, tweeted that a mother and infant died when a tree fell on their house; the baby's father was injured. A 78-year-old man was electrocuted attempting to connect extension cords while another man died when he was blown down by high winds while checking on his hunting dogs, a county spokesman said.
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.
Properties within one mile of the river were hastily evacuated on Saturday.
"I feel like the dumbest human being who ever walked the face of the earth", he said.
As of 8 p.m., Florence was centered about 65 miles (100 kilometers) east-southeast of Columbia, the SC capital, crawling west at 2 mph (4 kph) - not even as fast as a person walking. It came ashore along a mostly boarded-up, emptied-out stretch of coastline.
'Uninvited brute': 4 dead as Florence drenches the Carolinas
Hurricane-force winds extended 130 kilometres from its centre, and tropical-storm-force winds up to 315 kilometres. The town's public information officer, Colleen Roberts, told CNN 150 more people were awaiting rescue.
Authorities on Saturday warned residents displaced by a killer hurricane that its devastation was far from over, as Florence dumped "epic amounts of rainfall" across the southeastern United States, bringing catastrophic flooding. 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.
Electricity remained out for much of the city, with power lines lying across many roads like wet strands of spaghetti. The eye moved from sea to land at Wrightsville Beach in North Carolina.
About 10 million people could be affected by the storm.
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.
Florence was seen as a major test for the Federal Emergency Management Agency, which was heavily criticized as slow and unprepared past year for Hurricane Maria in Puerto Rico, where the death toll was put at almost 3,000.
Officials have declared states of emergency in several states, including in the Carolinas, Georgia, Virginia and Maryland, where coastal areas are still recovering from summer storms. That's enough to fill the Chesapeake Bay or cover the entire state of Texas with almost 4 inches (10 centimeters) of water, he calculated.
The rest of SC into western North Carolina and southwest Virginia is expected to report 5 to 10 inches of additional rainfall, with isolated cases of 15 inches.
"What we want to try to do is to minimize the time that people spend in their shelters that they're in right now", Sprayberry said.
The remnants of Florence are expected to hit the peaks of western North Carolina in a couple of days.
Major river flooding expected to continue into early next week. "That's why we've been preaching to people that you have to get away from the water". "It's making it hard for us to move valuable resources to areas in need". "Many people who think the storm has missed them have yet to see its threat".