Hurricane Florence has been downgraded to a category two storm as it approaches the US but officials still warn of a "disaster at the doorstep".
Some 10 million people are now under some form of storm watch.
Florence may now be heading further south, and Georgia is the latest state to declare an emergency.
It joins North and South Carolina, Virginia, Maryland and Washington DC.
Florence's winds may have dropped to 110mph (175km/h) but its slow-moving nature could mean it lingers for days, bringing catastrophic flooding.
What makes Florence so dangerous?
The biggest danger to life could be from storm surges, which are still predicted to be as high as 13ft (4m) between Cape Fear and Cape Lookout in North Carolina, areas that could also see up to 40in (101cm) of rain.
There will be hurricane-force winds up to 80 miles from the centre of the storm, meteorologists say.
President Donald Trump issued a video message saying: "This is going to be one of the biggest ones to ever hit our country... Protection of life is the absolute highest priority."
A National Weather Service forecaster said: "This will likely be the storm of a lifetime for portions of the Carolina coast.
What damage could it cause?
Florence could wreak more than $170bn (£130bn) of havoc and damage nearly 759,000 homes and businesses, says analytics firm CoreLogic.
Energy companies warned Florence could knock out power in some areas for weeks