Rescuers trying to reach drenched and stunned victims of Hurricane Dorian in the Bahamas fanned out across a blasted landscape of smashed and flooded homes on Wednesday, while disaster relief organisations rushed to bring in food and medicine.
The official death toll stood at seven but was certain to rise.
The full magnitude of the crisis in the islands of Abaco and Grand Bahama was still coming into focus, with rescue crews yet to reach some of the hardest-hit areas.
"Right now there are just a lot of unknowns," Parliament member Iram Lewis said in Grand Bahama in the wake of the most powerful hurricane on record ever to hit the country. "We need help."
Some storm victims remained on rooftops, awaiting rescue, according to media reports early on Wednesday.
Dorian, meanwhile, pushed its way northward off the Florida shoreline with reduced but still-dangerous 105 mph 165 km/h) winds on a projected course that could sideswipe Georgia, as well as North and South Carolina. An estimated three million people in the four states were warned to evacuate.
The storm mauled the Bahamas for over a day and a half with winds up to 185 mph (295km/h) and torrential rains, swamping neighbourhoods in muddy brown floodwaters and destroying or severely damaging thousands of homes.
Josh Morgerman, who went to the Great Abaco Island on August 31, said Dorian was the most intense storm he had experienced in three decades of chasing hurricanes.
"Thought I was playing it safe by riding it out in a solid-concrete school on a hill in Marsh Harbour," he tweeted. "Thought wrong ... Winds pounded the building with the force of a thousand sledgehammers."
When the storm's eye passed over the island, Morgerman said he fled to a better-built government building that he found filled with others who had escaped collapsed houses.
Prime Minister Hubert Minnis said the Bahamas is "in the midst of one of the greatest national crises in our country's history".
He said he expects the number of dead to rise.
National Security Minister Marvin Dames said rescue teams were fanning out across the northern Bahamas as the winds and rain subsided, with more than 600 police officers and marines in Grand Bahama and an additional 100 in Abaco.
"The devastation is unlike anything that we've ever seen before," he said. "We're beginning to get on the ground, get our people in the right places. We have a lot of work in the days and weeks and months ahead."
Rescuers used jet skis, boats and even a bulldozer to reach children and adults trapped by the swirling waters, while the US Coast Guard, Britain's Royal Navy and relief organisations tried to get food and medicine to survivors and take the most desperate people to safety.
Five Coast Guard helicopters ran near-hourly flights to stricken Abaco, flying people to the main hospital in the capital, Nassau.
Health Minister Duane Sands said the government was airlifting 25 doctors, nurses and other health workers to Abaco and hoped to bring in mental health workers soon.
"The situation is under control in Abaco," he said. "In Grand Bahama, today will tell the magnitude of the problem."
Abaco and Grand Bahama islands, with a combined population of about 70,000, are known for their marinas, golf courses and all-inclusive resorts.
Red Cross spokesman Matthew Cochrane said on Tuesday that more than 13,000 houses, or about 45 percent of the homes on Grand Bahama and Abaco, were believed to be severely damaged or destroyed. UN and Red Cross officials said tens of thousands of people will need food and clean drinking water.
"It's total devastation. It's decimated. Apocalyptic," said Lia Head-Rigby, who helps run a hurricane relief group and flew over Abaco. "It's not rebuilding something that was there; we have to start again."
She said her representative on Abaco told her there were "a lot more dead".
At 8am (12:00 GMT) on Wednesday, Dorian was centred about 95 miles (144km) northeast of Daytona Beach, Florida, moving northwest at eight mph (13km/h). Hurricane-force winds extended up to 60 miles (95km) from its centre.
Dorian was expected to pass dangerously close to Georgia and perhaps strike South Carolina or North Carolina on Thursday or Friday with the potential for more than a metre of rain in some spots. The National Hurricane Center warned that the storm is likely to cause storm surge and severe flooding even if the hurricane's core does not blow ashore.
"Don't tough it out. Get out," said US Federal Emergency Management Agency official Carlos Castillo.
Across the Southeast, interstate highways leading away from beaches were turned into one-way evacuation routes. Walt Disney World and Universal closed their theme parks in Orlando. The Navy ordered ships at its huge base in Norfolk, Virginia, to head out to sea for safety, and warplanes at Langley Air Force Base in Hampton, Virginia, were being moved inland to Ohio.
Having seen storms swamp his home on the Georgia coast in 2016 and 2017, Joey Spalding of Tybee Island decided to empty his house and stay at a friend's apartment nearby rather than take any chances with Dorian.
He packed a U-Haul truck with tables, chairs, a chest of drawers, tools - virtually all of his furnishings except for his mattress and a large TV - and planned to park it on higher ground. He also planned to shroud his house in plastic wrap up to shoulder height and pile sandbags in front of the doors.
"In this case, I don't have to come into a house full of junk," he said. "I'm learning a little as I go."