43 people died during the power outage, and widespread flooding

At least 43 people died and millions were left without power on Friday as Hurricane Helene roared through the southeastern US.

Officials continued rescues by boats, helicopters and trucks to help those trapped in the floodwaters – including about 50 staff and patients crammed onto the roof of a flooded Tennessee hospital.

It was the strongest hurricane on record to hit Florida’s Big Bend and moved north into Georgia and the Carolinas after making landfall Thursday night.

Insurance companies and financial institutions say the damage caused by the storm could reach billions of dollars.

Roads and houses were submerged on Friday, one family explained to BBC News that they had to swim out of their house to safety. Although Helene has weakened significantly, forecasters are warning that strong winds, flooding and the threat of hurricanes may continue.

Helene, a category four hurricane, made landfall Thursday night and remained a hurricane six hours after landfall, according to the Federal Emergency Management Agency (FEMA).

The National Hurricane Center (NHC) said the storm surge – which raised water levels significantly due to strong winds blowing water onto the coast – reached more than 15ft (4.5m) above ground level in parts of Florida’s coast.

The NHC said the storm should subside before the weekend but the threat of strong winds and flooding will remain, including possible landslides.

Up to 20in (50cm) of rain is still possible in places.

This storm is the 14th strongest to hit the US since records began. At about 420 miles (675 km) in diameter, it is behind only two other hurricanes – Ida in 2017 and Opal in 1996, both of which were 460 miles in diameter.

Because of its size, the impact of strong winds and heavy rain spread across Florida, Georgia, Tennessee and the Carolinas.

At least eight people have died in Florida since Friday, including at least five people off the coast of Pinellas County, said County Sheriff Bob Gualtieri.

This region includes the city of St. Petersburg on Florida’s Gulf Coast.

Florida Governor Ron DeSantis said one person died after a road sign fell on their car and another when a tree fell on their home.

After hitting Florida, the storm continued on a dangerous path north of Georgia – leaving at least 15 people dead – including first responders, Governor Brian Kemp said.

A suspected tornado in Wheeler County, central Georgia, left two people dead when the tornado overturned a trailer, authorities said.

Kemp ordered 1,000 soldiers to help with rescue efforts across the region. Georgia’s governor said Friday that more than 150 roads were closed, 1,300 road signs were out across the state and people were still trapped in buildings.

In South Carolina, at least 17 people died, according to CBS News, the BBC’s US partner. Neighboring North Carolina saw at least two people die in the storm, one in a car crash and another when a tree fell on a home in Charlotte, Governor Roy Cooper said.

The state also saw two confirmed tornadoes, which destroyed 11 buildings and injured 15 people, the National Service said.

Another person was killed in Virginia, said the governor of the state, Glenn Youngkin, in a press conference on Friday.

Across the East, more than 3 million homes and businesses were without power late Friday, according to the poweroutage.us tracking site.

First responders were trying to rescue people, using helicopters, boats and trucks to help people trapped in flooded homes. In North Carolina alone, more than 100 people have been rescued, Cooper said.

In Tennessee, 58 patients and staff were trapped on the roof of a hospital in Erwin on Friday. Fast-moving water in the Nolichucky River prevented boats from conducting rescue operations, and strong winds prevented a helicopter rescue.

The group was later taken to a safe place after the intervention of helicopters from the Tennessee National Guard and the Virginia State Police.

In Pasco County, north of Tampa on Florida’s Gulf Coast, 65 people were rescued. Guests at the Ramada Inn in Manatee County were also rescued as floodwaters poured into the hotel.

And in Suwannee County in the north, authorities reported “massive destruction”, trees falling on houses.

On Florida’s Gulf Coast, Briana Gagnier told the BBC that she and her family saw water entering their Holmes Beach home and began moving their belongings onto tables and beds before hearing a loud noise.

“My family and I all looked at each other,” he said. “Then the water started pouring.”

Ms Gagnier said she took her pets, her wallet and portable chargers and swam out of their home with her family. The water reached their shoulders.

“We also encourage all communities to continue to listen to local officials,” FEMA Deputy Administrator Erik Hooks said Friday.

“Just because the storm has passed where you are doesn’t mean you are safe to leave your home.”

Officials also reminded residents that the effects of the storm are “not over yet” and urged residents to remain vigilant.

Hurricanes need sea temperatures above 27C (80F) to fuel.

With exceptionally warm water in the Gulf at 30-32C, the sea surface is about two degrees Celsius above normal for the time of year.

Florida’s 220-mile Big Bend coastline is where Hurricane Idalia will hit in 2023. The area was also hit by Hurricane Debby last month.

There could be as many as 25 named storms by 2024, the National Oceanic and Atmospheric Administration (NOAA) warned earlier this year.

Between eight and 13 of those storms could become hurricanes and several already have, including Helene.

More storms may be on the way as the official end of the storms won’t come until November 30, officials warned.