The southeastern US has begun a huge clean-up and recovery effort and the death toll has climbed towards 100 after Hurricane Helene knocked out power for millions, destroyed roads and bridges and caused dramatic flooding from Florida to Virginia.
The storm's winds, rain and storm surge killed at least 90 people in North Carolina, South Carolina, Georgia, Florida, Tennessee and Virginia, according to a Reuters tally of state and local officials.
Officials feared more bodies would be discovered.
With phone towers down across the region, hundreds of people had yet to make contact with loved ones and were listed as unaccounted for.
Damage estimates ranged from $US15 billion to more than $US100 billion ($A22 billion-$A144 billion), insurers and forecasters said at the weekend as water systems, communications and critical transportation routes were affected.
Property damage and lost economic output will become clearer as officials assess the destruction.
In North Carolina, nearly all the deaths were in Buncombe County, where 30 people died, Sheriff Quentin Miller told a video conference call with reporters.
County manager Avril Pinder said she was asking the state for emergency food and drinking water.
Streets in the picturesque city of Asheville were submerged in floodwater.
"This is a devastating catastrophe of historic proportions," Governor Roy Cooper told CNN.
"People that I talk to in western North Carolina say they have never seen anything like this."
Search and rescue teams from 19 states and the US government have converged on the state, Cooper said, adding some roads could take months to repair.
In Flat Rock, North Carolina, there were widespread blackouts, and people waited hours in line for petrol.
Roughly 2.7 million customers throughout the South were without power on Sunday, a US Energy Department official said, down 40 per cent from Friday after unprecedented storm surges, ferocious winds and perilous conditions extended hundreds of kilometres inland.
South Carolina reported 25 dead, Georgia 17 and Florida 11, according to the governors of those states.
CNN reported a total of 93 dead across the South, citing state and local officials.
President Joe Biden planned to visit affected areas this week, once he could do so without disrupting emergency services, the White House said.
"It's tragic," Biden told reporters on Sunday, pledging recovery assistance after declaring major disasters in Florida and North Carolina and emergencies for Florida, North Carolina Tennessee, South Carolina, Georgia, Virginia, and Alabama.
"You saw the photographs. It's stunning."
Vice-President and Democratic presidential candidate Kamala Harris planned to cut short a campaign trip in Nevada on Monday to take part in briefings in Washington on the hurricane response and would visit the region when doing so would not impede the response, a White House official said.
Republican presidential candidate Donald Trump would visit Valdosta, Georgia, on Monday to receive a briefing on storm damage and "facilitate the distribution of relief supplies", his campaign said.
Helene slammed into Florida's Gulf Coast on Thursday night, triggering days of driving rain and destroying homes that had stood for decades.
In coastal Steinhatchee, a storm surge of to three metres moved mobile homes, the weather service said.
Other areas had a storm surge of 4.5m.
In the nearby tiny community of Spring Warrior Fish Camp, people were surveying the damage on Saturday and still waiting for emergency or first responder aid.
"No one thinks of us back here," said David Hall, as he and his wife dug through seagrass and dead fish in the office of the hotel they owned.
Many of the community's homes are built on stilts because of a local ordinance and survived heavy damage.
Kristin Macqueen was helping friends clean up after their house was destroyed in nearby Keaton Beach.
"It's complete devastation," she said. "Houses have just been ripped off their slabs."
