A mother and baby were killed when a tree fell on their home in Wilmington, North Carolina.
Heavy rain is expected to continue all day, and the northern coastline of SC is still under a storm surge warning, but the National Weather Service's latest flooding projections show less rivers forecast to reach major flood levels than previously thought. The child's injured father was taken to hospital.
A woman in Hampstead, in Pender County, died of an apparent heart attack after emergency crews could not clear debris to get to her.
The region is being pounded with rain from the slow-moving storm, causing the risk of catastrophic flooding.
New Bern has been one of the hardest hit areas by Florence, experiencing a 10-and-a-half-foot storm surge.
New Bern resident Dan Eudy said he and his brother were awakened on Thursday night by the sound of a boat ramming against his front porch.
Cooper said Florence was set to cover nearly all of North Carolina in several feet of water. The storm was moving very slowly westward at about 6 miles per hour.
That kind of scenario is likely to repeat itself all over communities in Eastern North Carolina, as swollen rivers flood towns and the pouring rain adds to the misery.
In Jacksonville, North Carolina, next to Camp Lejeune, firefighters and police fought wind and rain as they went door to door to pull more than 60 people out as the Triangle Motor Inn began to crumble.
Hurricane Florence made landfall near Wrightsville Beach, N.C., around 7:15 a.m. ET Friday morning, the National Hurricane Center said. Downed trees blocked the road, making it impossible for paramedics to get to her.
"WE ARE COMING TO GET YOU", the city tweeted during the height of the storm.
"We're not going to be satisfied until the last resident is rescued and in a shelter, and then we can assess damages and go from there", New Bern Mayor Dana Outlaw said, according to the Herald Sun of North Carolina.
Meteorologist Ryan Maue of weathermodels.com said Florence could dump a staggering 68 trillion litres of rain over a week on North Carolina, South Carolina, Virginia, Georgia, Tennessee, Kentucky and Maryland.
Across North Carolina, more than 65 school districts are closed, and almost all University of North Carolina system schools have cancelled classes.
"For a meandering storm, the biggest concern - as we saw with Harvey - is the huge amount of rainfall", said Chris Landsea, chief of tropical analysis and forecast branch at the National Hurricane Center.
Forecasters said "catastrophic" freshwater flooding was expected along waterways far from the coast of North and SC.
Florence had been a Category 3 hurricane with 120 miles per hour winds on Thursday but dropped to Category 1 before coming ashore. "The combination of a unsafe storm surge and the tide will cause normally dry areas near the coast to be flooded by rising waters moving inland from the shoreline".