The International Red Cross says 1.2 million people have already been affected by Irma – a number that could rise to 26 million.

The bill for loss and damage could hit US$120 billion in the United States and Caribbean, according to data modelling firm Enki Research.

Barbuda

Irma hit the tiny Caribbean island of Barbuda on Wednesday. The island suffered “absolute devastation,” with up to 30 per cent of properties demolished, Prime Minister Gaston Browne said.

One person is known to have died on the island of 1,600 residents, apparently a child whose family was trying to get to safer ground.

St Barts and St Martin

Irma then slammed into the holiday islands of St Barts and St Martin, wielding monster winds and torrential rain.

St Martin is divided between France and the Netherlands. France said 10 people had died, while the Netherlands said the storm killed two on the Dutch side, called Sint Maarten.

Both governments said the damage was enormous and condemned looting.

Virgin Islands

At least four people were killed in the US Virgin Islands

“We lost a significant and a good number of assets ... in terms of fire stations, police stations,” Governor Kenneth Mapp said on Facebook, adding that the region’s main health facility, the Schneider Regional Medical Centre, lost its roof.

In the British Virgin Islands, Governor Gus Jaspert declared a state of emergency and said “there have sadly been reports of casualties and fatalities”

Puerto Rico

At least two people were killed in the US territory of Puerto Rico, and more than half of its three million residents were without power after rivers broke their banks in the centre and north of the island.

Dominican Republic

The storm tore past the Dominican Republic Thursday, bringing torrential rain. Some 20,000 people were evacuated and more than 2,000 homes hit by floods.

Haiti

Irma brought flooding and caused several injuries in Haiti, but passed further north than had been forecast, sparing the impoverished island the worst.

In northwest Haiti, a motorcyclist was missing after trying to cross a flooded river and a number of roads were washed out.

Bahamas

The Bahamas escaped the worst of Irma’s wrath, with no casualties or major infrastructure damages reported Friday.

But reports indicated that there were several downed power lines, toppled trees, debris and roofs damaged.

Cuba

Irma made landfall on the island’s Camaguey Archipelago late Friday. Close to a million people have left their homes to stay with relatives or in shelters.

The Caribbean’s biggest island, Cuba had already evacuated 10,000 foreign tourists from beach resorts and raised its disaster alert level to maximum ahead of Irma’s arrival.

Where next?

Irma is expected to strike the Florida Keys late Saturday and Sunday before moving inland to Georgia and South Carolina, according to the US National Hurricane Centre.

Authorities have ordered 5.6 million to evacuate around a quarter of Florida’s population and many residents have joined a mass exodus.

The US military is mobilising thousands of troops and deploying several large ships to help with evacuations and humanitarian relief.

US President Donald Trump has already declared a state of emergency for Puerto Rico, the US Virgin Islands and Florida, while Georgia ordered the evacuation of the city of Savannah and other coastal areas.

More hurricanes

St Barts and St Martin have been placed on alert ahead of its projected passage over the islands.

It was later downgraded from Category One to a tropical storm, but the US National Hurricane Centre warned it was bringing rains likely to cause “life-threatening flash floods and mudslides, especially in areas of mountainous terrain”.