Residents across the south-eastern US were beginning the clean-up from Hurricane Idalia on Thursday as Joe Biden signed a major disaster declaration for Florida and the weakened but still powerful tropical storm dumped torrents of rain in North Carolina and Virginia.

The worst of the devastation was evident along Florida’s Gulf coast, where Idalia tore ashore on Wednesday as a category 3 hurricane with gusts of 160mph and sent a surge of seawater of up to 16ft far inland through vulnerable low-lying communities.

President Joe Biden said Thursday that he plans to travel to Florida Saturday morning after Hurricane Idalia battered the state earlier this week.

“I’m going to Florida Saturday morning,” Biden said, after delivering brief remarks at Federal Emergency Management Agency headquarters after thanking staff for their work responding to the storm.

Roofs were torn from some buildings, houses were submerged by water from the Gulf of Mexico and flash flooding, and thousands of downed trees and power lines littered a trail from Florida’s west coast to Wilmington, North Carolina.

Florida’s Republican governor, Ron DeSantis, toured some of the worst-hit areas on Thursday afternoon with Deanne Criswell, administrator of the Federal Emergency Management Agency, and said he was “heartbroken” at what he saw.

He said there was one confirmed fatality in a storm-related traffic accident.

Torrential rain and significant inland and coastal flooding, meanwhile, continued in Georgia, the Carolinas and Virginia, as forecasters warned that the grip of Idalia, still a tropical storm with winds of 65mph, would not be fully loosened until late Thursday or early Friday.