Hurricane Irma ripped through the Caribbean on Friday, with its violent winds and torrential rains leaving a trail of devastation and killing 12 as it barreled towards the United States where up to a million people were told to flee.
With the monster storm expected to reach the American south by the weekend, coastal areas of Florida and Georgia were battening down the hatches and carrying out the biggest evacuation since 2005.
"The entire southeastern United States better wake up and pay attention," warned US federal emergency chief Brock Long. "It will be truly devastating."
Barreling across the Caribbean, the rare Category Five storm laid waste to a series of tiny islands like St Martin, where 60 percent of homes were wrecked, before slamming the US Virgin Islands and Puerto Rico.
As it raged westwards, Irma packed winds of up to 185 miles per hour (295 kilometers per hour), an intensity it sustained for 33 hours -- the longest of any storm since satellite monitoring began in the 1970s.
On many islands, violent winds had ripped roofs or facades off homes and businesses, tossing cars and even shipping containers aside like matchsticks.
So far, 1.2 million people have been affected by Irma, the International Red Cross said.
But that number looks set to rise -- possibly reaching as many as 26 million.
At least two people were killed in Puerto Rico, a senior rescue official said.
More than half of the territory's population of three million was without power, with rivers breaking their banks in the center and north of the island.
Ahead of the storm, Governor Ricardo Rossello activated the National Guard and opened storm shelters sufficient for up to 62,000 people.
Another four people were killed on the US Virgin Islands, with the governor's office saying a number of badly injured people had been airlifted to Puerto Rico.
St Martin, a pristine island resort divided between France and the Netherlands, also suffered the full fury of the storm.
France said four had died and 50 were injured, two of them seriously. Officials also said six out of 10 homes were so badly damaged that they were uninhabitable.
Insurance officials in Paris believe the cost of storm damage on France's Caribbean islands to be well over 200 million euros ($240 million).
On the Dutch side of the island, one person died and several others were wounded, officials said.
Both France and the Netherlands have quickly mobilized to join in search and rescue efforts and provide food and water to their respective citizens.
Britain also said the hurricane had caused "great devastation" in the British Virgin Islands, with foreign minister Boris Johnson saying London had sent teams there to distribute aid.
Two British warships have also been deployed to help as the storm heads for Turks and Caicos, an archipelago of around 30 islands that is a self-governing part of the United Kingdom.
Irma also laid waste to tiny Barbuda which suffered "absolute devastation," with up to 30 percent of properties demolished, Prime Minister Gaston Browne said.
Rescue teams were scouring the island for survivors, an AFP correspondent said, as some 300 people without shelter were evacuated to Antigua.
One person died on the island of 1,600 residents, apparently a child whose family was trying to get to safer ground.
As of early Friday, the eye of the storm was just north of Great Inagua, at the southern tip of the Bahamas.
As the storm swept past Haiti, people were largely left to face the hurricane's fury alone as authorities showed little sign of preparing for what forecasters said could be a catastrophic event.
In the Dominican Republic, which shares the island of Hispaniola with Haiti, torrential rain and powerful winds whipped the northern and eastern coasts, leaving 17 districts cut offs as rivers burst their banks, emergency officials said.
Nearly 20,000 people were evacuated from their homes and more than 100 houses were destroyed.
Meanwhile in Cuba, some 10,000 foreign tourists were evacuated from beach resorts and officials hiked the disaster alert level to maximum.
Florida is expecting to face the brunt of the hurricane from Sunday, with forecasters warning of storm surges of up to 25 feet (almost eight meters) above normal tide levels.
Tourists in the popular Key West islands were packing their bags on a mandatory evacuation order, with a similar order for residents due to follow.
"We can't save you once the storm starts," Governor Rick Scott told a press conference.
After going for a walk along the beach in Miami, theology professor James Nickolos, 69, said there was a sense of impending doom.
"I had the feeling of watching a great beauty walking on a gang-plank to their death," he said.
Trump said he was "very concerned" about the situation but insisted that Florida was "as well prepared" as possible for the storm.
As Irma cut through the Caribbean, two other storms in the region were upgraded to hurricane status: Jose in the Atlantic Ocean and Katia in the Gulf of Mexico.
Katia, a Category One storm, is expected to hit the coast of the Mexican state of Veracruz sometime on Friday.
Jose, which is following Irma's path and was located east of the Lesser Antilles late on Thursday, strengthened to a Category Three event, packing winds of up to 120 miles per hour, the US National Hurricane Center said.