Editor's note: This is a developing story that is being constantly updated as the storm progresses.
Leaving a trail of devastation in Florida, Irma trudged north on Monday, flooding downtown Charleston, South Carolina, uprooting trees in Atlanta and cutting off coastal communities.
A weakened Irma -- downgraded to a tropical depression Monday night -- still packed power. At least three storm-related deaths were reported in Georgia and one in South Carolina. The deaths occurred mostly when tree limbs fell on victims during the tropical storm that stretched 650 miles from east to west, affecting at least nine states.
As Jacksonville, Florida, grappled with record storm surge, the level of the destruction became more apparent in the hard-hit Florida Keys at the southern tip of the state. Areas without water, power or communications are likely to remain so for some time.
Irma flooded portions of River Street in the tourist magnet city of Savannah, Georgia and forced police to temporarily shut Highway 80 leading to the barrier island community of Tybee Island. Water also filled The Battery, the downtown Charleston neighborhood where the Ashley and Cooper rivers meet. Charleston police asked residents to avoid downtown in anticipation of high tide.
Waters in Charleston Harbor peaked at nearly 10 feet high, the city's third-highest reading, topping Hurricane Matthew in 2016, said CNN meteorologist Taylor Ward.
Parts of coastal Georgia and South Carolina remained under storm surge warning late Monday.
Irma will continue to weaken, but the rain and wind will spread further north. The storm was moving towards Alabama late Monday. It is forecast to move to Tennessee on Tuesday before fizzling out later this week, forecasters said.