At least five people have been killed as Tropical Storm Debby made landfall, moving across some of America’s most historic southern cities.

Record-setting rain caused flash flooding after slamming into Florida, forcing the rescue of hundreds from flooded homes.

“Hunker down,” Van Johnson, mayor of Savannah, Georgia, told residents in a social media livestream. “Expect that it will be a rough day.”

Flash flood warnings were issued in Savannah, Georgia, and Charleston, South Carolina, among other areas of coastal Georgia and South Carolina. Both Savannah and Charleston announced curfews Monday night into Tuesday.

Tropical Weather Debby Florida
Flood water blocks a section of Dodecanese Blvd at the Tarpon Springs (Douglas R Clifford/Tampa Bay Times via AP)

In South Carolina, Charleston County interim emergency director Ben Webster called Debby a “historic and potentially unprecedented event” three times in a 90-second briefing Monday.

In addition to the curfew, the city of Charleston’s emergency plan includes sandbags for residents, opening parking garages so residents can park their cars above floodwaters and an online mapping system that shows which roads are closed due to flooding.

In South Carolina a tornado touched down on Monday night, damaging trees, and homes and taking down power lines, the Colleton County Sheriff’s Office said on social media. No injuries were immediately reported, officials said.

The National Weather Service continued issuing tornado warnings well into Monday night for parts of the state including in the island town of Hilton Head.

Debby made landfall along the Gulf Coast of Florida early on Monday as a Category 1 hurricane. It has weakened to a tropical storm and is moving slowly, drenching and bringing areas of catastrophic flooding across portions of eastern Georgia, the coastal plain of South Carolina and southeast North Carolina through Wednesday.

APTOPIX Tropical Storm Florida
A driver negotiates a flooded street (Max Chesnes/Tampa Bay Times via AP)

About 500 people were rescued on Monday from flooded homes in Sarasota, Florida, a beach city popular with tourists, the Sarasota Police Department said in a social media post. Just north of Sarasota, officials in Manatee County said in a news release that 186 people were rescued from flood waters.

“Essentially we’ve had twice the amount of the rain that was predicted for us to have,” Sarasota County fire chief David Rathbun said on social media.

Florida Governor Ron DeSantis warned that the state could continue to see threats as waterways north of the border fill up and flow south.

“It is a very saturating, wet storm,” he said. “When they crest and the water that’s going to come down from Georgia, it’s just something that we’re going to be on alert for not just throughout today, but for the next week.”

Five people had died due to the storm as of Monday night, including a truck driver on Interstate 75 in the Tampa area after he lost control of his tractor-trailer, which flipped over a concrete wall and dangled over the edge before the cab dropped into the water below.

Sheriff’s office divers located the driver, a 64-year-old man from Mississippi, in the cab 40 feet (12 metres) below the surface, according to the Florida Highway Patrol.

A 13-year-old boy died on Monday morning after a tree fell on a mobile home southwest of Gainesville, Florida, according to the Levy County Sheriff’s Office. In Dixie County, just east of where the storm made landfall, a 38-year-old woman and a 12-year-old boy died in a car crash on wet roads Sunday night.

In southern Georgia, a 19-year-old man died when a large tree fell onto a porch at a home in Moultrie, The Atlanta Journal-Constitution reported.

Nearly 160,000 customers remained without power in Florida and Georgia on Monday night, down from a peak of more than 350,000, according to PowerOutage.us and Georgia Electric Membership Corp.

President Joe Biden approved a request from South Carolina’s governor for an emergency declaration, following his earlier approval of a similar request from Florida. Georgia Governor Brian Kemp said he has asked Mr Biden to issue a pre-emptive federal emergency declaration to speed the flow of federal aid to the state.

North Carolina is also under a state of emergency after Governor Roy Cooper declared it in an executive order signed on Monday.