About 6.5 million homes in Florida, two-thirds of the total, are without power after Hurricane Irma cut a deadly path through the state, officials say.
Relief operations are under way and engineers are working to restore power, but many areas remain stranded.
The islands of the Florida Keys and western parts of the US state bore the brunt of the category-four hurricane.
Irma hit Florida on Sunday and weakened to a tropical storm before becoming a tropical depression early on Tuesday.
The storm was downgraded as it moved north towards Atlanta, with maximum sustained winds of 56km/h (35mph) later recorded, the National Hurricane Center (NHC) said in a statement.
The NHC statement added that while heavy rain was expected to continue across south-eastern states, all storm surge and tropical storm warnings had been discontinued.
Media reports link at least four deaths to the storm in Florida. Last week it killed at least 37 people in Caribbean islands. -BBC