Hurricane Helene kills at least 40 - as dozens rescued from Tennessee hospital roof in 'dangerous operation'

At least 40 people have been killed across four states after Hurricane Helene barrelled its way across southeastern US.

Emergency crews are racing to rescue people trapped in flooded homes after Helene struck the coast of Florida as a highly destructive Category 4 storm.

It generated a massive storm surge, wreaking a trail of destruction extending hundreds of miles north.

Millions are without power in Florida and neighbouring states.

Meanwhile, dozens of patients and staff have been rescued from the roof of a flooded Tennessee hospital following a "dangerous rescue operation".

Tennessee Senator Bill Hagerty said more than 50 people are now safe after becoming stranded on the Unicoi County Hospital.

The hospital was engulfed in "extremely dangerous and rapidly moving water", according to Tennessee's Ballad Health, making a boat rescue too treacherous.

A police helicopter was ultimately able to land on the roof after other helicopters failed to reach the hospital due to the storm's winds.

Local official Michael Baker told Sky News the flooding was "unprecedented".

"We've never seen anything like this," he said.

As of early afternoon, Helene, which has been downgraded to a tropical depression, was packing maximum sustained winds of 35 mph (55 kph) as it slowed over Tennessee and Kentucky, the National Hurricane Center said.

It struck overnight with maximum sustained winds of 140 mph (225 kph) in the rural Big Bend area, the northwestern part of Florida.

The National Hurricane Center said preliminary information shows water levels reached more than 15ft above ground in that region.

US President Joe Biden has approved emergency declaration requests from the governors of several southern states affected by Helene.

Georgia, Florida, Alabama, North Carolina and South Carolina are being supported by emergency response personnel including search and rescue teams, medical support staff and engineering experts.

Georgia Governor Brian Kemp has said dozens of people are trapped in buildings damaged by the storm, with multiple hospitals in southern Georgia without power.

In western North Carolina, Rutherford County emergency officials have told residents near the Lake Lure Dam to immediately evacuate to higher ground, warning "Dam failure imminent".

Meanwhile, Florida Governor Ron DeSantis said the damage from Helene in the area appears to be greater than the combined damage of Idalia and Hurricane Debby in August. "It's demoralizing," he said.

Many stranded in places like Tampa could only be reached by boat, with officials warning the water could contain live wires, sewage, sharp objects and other debris.

More than four million properties are without power across Florida, Georgia, the Carolinas, Virginia, Kentucky, Tennessee and Ohio, according to the logging website, PowerOutage.

Prior to the hurricane making landfall, officials in Florida begged residents to evacuate. The sheriff's office in rural Taylor County issued a chilling warning to those who refused to leave.

"Please write your name, birthday, and important information on your arm or leg in a permanent marker so that you can be identified and family notified," the post on Facebook said.

Forecasters now expect the storm to continue weakening across Tennessee and Kentucky.

It is feared heavy rain over the Appalachian Mountains could cause mudslides and flash flooding.

(c) Sky News 2024: Hurricane Helene kills at least 40 - as dozens rescued from Tennessee hospital roof in 'dangerous operation'