FLORIDA — One of the most dangerous storms to hit the US in years has left 2.4 million homes and businesses in Florida without power and floodwaters surging inland.

Hurricane Ian made landfall at around 15:10 local time (19:10 GMT) on Wednesday, smashing into the coast with wind speeds of up to 241km/h (150mph).

Dramatic scenes saw a hospital roof blown off, cars submerged and trees ripped out of the ground.

The category four hurricane was later downgraded to a tropical storm.

However, Floridians were warned that the most dangerous 24 hours lay ahead and the mayor of Tampa urged people to shelter in place through the night into Thursday morning.

"We are going to get the majority of the rain and the higher winds starting about 20:00, and they are going to last throughout the night," Jane Castor said during a Wednesday evening briefing.

In a message posted on Facebook, the Weather Prediction Center told residents in the Central Florida Peninsula to expect "widespread life-threatening, catastrophic flash and urban flooding" continuing into Friday morning, with potentially up to 76cm (30ins) of rain falling locally.

Residents were ordered to leave their homes, but many have decided to remain and seek shelter indoors.

Mark Pritchett, who lives in the city of Venice, some 95km (60 miles) south of Tampa, described the "terrifying" moment he stepped outside his home as the hurricane made its way across the Gulf of Mexico.

"Rain shooting like needles. My street is a river," he said in a text message to the Associated Press news agency.

In Lee County - the south-west region where Ian made landfall - police were prevented from responding to reports of looting at a petrol station because of the storm damage.

As a result, a curfew has been declared "until further notice".

Lee County Manager Roger Desjarlais said that the Fort Myers community had "been - to some extent - decimated". According to news agency AFP, some neighborhoods in the city of 80,000 had been left resembling lakes.

State Governor Ron DeSantis described Ian as the "biggest flood event" south-west Florida had ever seen, and announced that 7,000 National Guard troops are ready to lead rescue operations in flood zones.

President Joe Biden will receive a briefing on Thursday from the Federal Emergency Management Agency.

Ian is now continuing to move north through Florida. Jacksonville International Airport, based in north-east Florida, canceled all flights scheduled for Thursday.

The storm is forecast to emerge into the Atlantic by Thursday morning.

It is expected to reach Georgia and South Carolina on Friday. Virginia has also joined Georgia, North Carolina, South Carolina and Florida by declaring a state of emergency.

Cuba's western coast was hit by Hurricane Ian on Tuesday. Power has now been restored in some areas after the island was plunged into a total blackout. Two people are understood to have been killed in Cuba and more than 20 Cuban migrants are believed to be missing at sea. — BBC