winds were holding at 45 miles per hour (75 kph), with higher gusts east of the storm's center.
The worst natural disaster in North Carolina history was Hurricane Floyd in 1999, which dumped almost 2 feet (60 centimeters) of rain and flooded a broad swath of the coastal plain, swamping whole towns and dozens of hog farm lagoons containing millions of gallons (liters) of untreated urine and feces. Police guarded the door of one store, and only 10 people were allowed inside at a time.
Officials said some 1.7 million people in the Carolinas and Virginia were warned to evacuate, but it's unclear how many did.
Atlantic Beach on North Carolina's Outer Banks islands had already received 30 inches (76 cm) of rain, the U.S. Geological Survey said.
By late afternoon, the center of the storm was about 25 miles northeast of Myrtle Beach, South Carolina, with maximum sustained winds of 70 mph. Rains have been relentless, and Florence continues to dump a "catastrophic" amount of water in its path. Some waterways in the Carolinas have already seen water levels 20 feet above average.
Transportation Secretary Jim Trogdon said Saturday that authorities were still assembling an alternate route for a 5-mile section of I-40 that is closed in both directions near the town of Warsaw, about 70 miles (115 kilometers) southeast of Raleigh.
As it moves near OH and West Virginia, it will become a remnant low.
Florence, a slow-moving system that forecasters say could release more than 3 feet (90 centimeters) of rain in places, could end up being even worse.
THESE shocking pictures show the true extent of Hurricane Florence - a powerful storm dubbed a "1,000 year event".
Two men were also killed in Lenoir County, North Carolina. It's not yet clear how the sixth person died.
The Navy says nearly 30 Virginia-based ships and 128 aircraft sent away from their bases in the Hampton Roads-area because of now-Tropical Storm Florence has been given the go-ahead to return.
Hurricane Florence made landfall near Wilmington on Friday morning, battering the coastal city with strong winds and torrential rain. "Be extremely careful and stay alert".
About 100 people still need to be rescued in New Bern, North Carolina, where some 4200 homes have been damaged, the mayor told CNN.
A woman and her child were killed were among those killed, when a tree fell into their house in Wilmington in North Carolina.
Householders were stranded in their cars, attics and on rooftops.
The number of service members deployed include 7,500 from the US Coast Guard and 6,500 from the National Guard, the Federal Emergency Management Agency said.
Stream gauges across the region showed water levels rising steadily, with forecasts calling for rivers to crest Sunday and Monday at or near record levels. The city remained without power on Friday night.
More than 430,000 people in North and SC are without power, and water is rising along the coast, where people in some towns have experienced dramatic rescues due to the towering storm surge.