Rescue crews were forced to seek shelter yesterday as Hurricane Dorian continued to batter the Bahamas.
The storm slowed to a near-standstill as 250kph winds pummelled the island chain, shredding roofs and hurling cars into the air.
So far, more than 13,000 homes have been destroyed or damaged by the hurricane.
As the system crawled at 2kph along Grand Bahama - the northernmost island in the archipelago - storm surges of seven metres were expected.
"We need you to bunker down," Kwasi Thompson, the minister of state for Grand Bahama, warned people.
"It's going to be another 10 to 12 hours that we're going to be bombarded with this."
Residents worried about the rising flood water contacted the emergency services but rescuers could not respond, such was the intensity of the "catastrophic storm".
By late morning, the flood water had reached roofs and the tops of palm trees in Grand Bahama.
In Freeport, the main town on Grand Bahama, Dave Mackey videoed water and floating debris surging around his house as the wind shrieked outside.
"We're pretty concerned right now because we're not yet at high tide," he said.
"Once we come out of it with our lives, we're happy."
On Sunday, Dorian churned over the Abaco Islands - which lie in the northern Bahamas - as people called radio stations and sent desperate messages on social media to find loved ones.
"We received catastrophic damage here in Abaco. Continue to pray for us," parliament member Darren Henfield told reporters.
There was a total blackout in New Providence, the archipelago's most populous island, said Quincy Parker, a spokesman for energy supplier Bahamas Power and Light, whose Abaco office was flattened by the storm.
"The reports out of Abaco are not good," he said.
On Sunday, Dorian's maximum sustained winds reached 297kph, with gusts up to 354kph.
Those speeds were equal to the 1935 Labour Day hurricane, the most powerful Atlantic hurricane to ever make landfall.
The only recorded storm that was more powerful was Hurricane Allen in 1980, with 305kph winds, though it did not make landfall at that strength.
Forecasters said Dorian was likely to begin pulling away from the Bahamas early today and head towards the south-east coast of the US.
The US National Hurricane Centre extended watches and warnings across the coasts of both Florida and Georgia.
Forecasters expected Dorian to stay off-shore, but cautioned that "only a small deviation" could draw the storm's dangerous core towards land.
On Sunday, South Carolina governor Henry McMaster ordered the mandatory evacuation of the state's entire coast.
The order, which covers more than 800,000 people, was due to take effect at noon yesterday, at which point state troopers were to close all major highways leading to the coast.
"We can't make everybody happy, but we believe we can keep everyone alive," said Mr McMaster.
Georgia governor Brian Kemp has also ordered the mandatory evacuation of the state's Atlantic coast.
Authorities in Florida ordered mandatory evacuations in some vulnerable coastal areas.
North Carolina governor Roy Cooper warned his state that it could see heavy rain, winds and floods later in the week.
Dorian first came ashore on Sunday at Elbow Cay in Abaco Islands. A seven-metre storm surge was reported.
The Bahamas archipelago is no stranger to hurricanes. Homes are required to have metal reinforced roof beams to withstand hurricane winds.
Risks are higher in poorer neighbourhoods, with wooden homes in low-lying areas.
After leaving the Bahamas, Dorian is forecast to drift north, spinning 64-80km off Florida, with hurricane-force wind speeds extending about 56km to the west.