Monster Hurricane Irma slammed into Caribbean islands on Wednesday after making landfall in Barbuda, packing ferocious winds and causing major flooding in low-lying areas.
As the rare Category Five storm barreled its way across the Caribbean, it brought gusting winds of up to 185 miles per hour (294 kilometers per hour), weather experts said.
After making landfall just before 0600 GMT in Barbuda, part of the twin island nation of Antigua and Barbuda, the hurricane swept on to French-run Saint Barthelemy, also known as St Barts, and Saint Martin, an island divided between France and the Netherlands.
Hurricane Irma has already caused "major damage" on several Caribbean islands, said French Overseas Territories Minister Annick Girardin, who announced she was leaving for the island of Guadeloupe on Wednesday.
The French weather office said Irma was "a historic hurricane (with) an unprecedented intensity over the Atlantic," with a French minister saying it had already "caused major damage" across St Barts and Saint Martin.
Coastal areas were being "battered extremely violently" by the sea, with the weather office logging winds of 244 kph (151 mph) before its monitoring equipment was destroyed by the hurricane.
With the islands on maximum alert ahead of the arrival of the strongest storm ever recorded in the Atlantic, France had raised the alarm over the fate of some 7,000 people who refused to seek shelter.
Dutch national broadcaster NOS also reported "enormous damage" on Saint Martin, with residents speaking of widespread destruction.
Saba Island and St Eustatius, two other Dutch-run territories to the south, were also hit.
The massive hurricane, which is beating a path northwest, was also expected to hit the larger French islands of Guadeloupe and Martinique.
With forecasters warning of catastrophe, including surges of up to 25 feet (7.6 metres) above normal tide levels, people evacuated tourist areas, stocked up on provisions, and packed into shelters across an area stretching as far north as Florida.
Irma, which is expected to stay in the region for days, follows hot on the heels of Hurricane Harvey which devastated swathes of Texas in late August.
Packed into shelters, many frightened residents were calling in to local radio stations to voice their concerns.
"I am just praying to God. Everything happens for a reason," said a woman called Kazia living on Antigua, where people were hunkering down in the dark after officials turned off the island's power supply as a safety precaution.
In mid-afternoon winds speeds there were logged at up to 90 mph.
Category Five is the highest on the scale for hurricanes in the Atlantic and Caribbean, and Irma is expected to reach the Virgin Islands and Puerto Rico by nightfall Wednesday.
Hurricanes of this category are rare. They can tear off roofing, shatter windows, uproot palm trees and turn them into deadly projectiles.
In Guadeloupe, schools and government offices in have been closed while hospitals stocked up on medicines, food and drinking water.
Across the island, shelters were packed with a mixture of local families and tourists.
"We came here to protect our little two-year-old boy," said Ludovic, a tourist who only gave his first name. "We hadn't prepared for this disaster scenario."
Florida is expecting to face the brunt of the storm from Friday night.
As the hurricane approached, US President Donald Trump declared a state of emergency in Florida, Puerto Rico and the US Virgin Islands, authorising federal funding to help local authorities respond.
"My team, which has done, and is doing, such a good job in Texas, is already in Florida. No rest for the weary!" he tweeted.
The Washington Post reported that Trump's luxury property on Saint Martin had been badly hit, without giving details.
Meanwhile British billionaire Richard Branson said he would be hunkering down in his concrete wine cellar to face Hurricane Irma as it hurtles closer to his private island of Necker in the British Virgin Islands.
Florida Governor Rick Scott said Irma, which comes barely a week after Harvey claimed at least 42 lives, posed "a severe threat to the entire state".
Tourists in the popular Key West islands were packing their bags on a mandatory evacuation order and were to begin leaving at sunrise on Wednesday, with a similar order for residents due to follow.
"We're emphatically telling people you must evacuate, you cannot afford to stay on an island with a Category 5 hurricane coming at you," said Monroe County emergency operations centre director Martin Senterfitt.
There were long queues as people rushed to get batteries, bottled water, groceries and fuel, while many cut trees around their homes and sought to tie down objects.
"People go crazy and buy up everything," 81-year-old resident Gladys Bosque told AFP.
"There's no water, no milk, there are very few cans -- and no cat food."
Florida Governor Rick Scott activated a 1,000 Guard members and the remaining 6,000 National Guard members will be reporting for duty no later than Friday morning.
In Puerto Rico, Governor Ricardo Rossello activated the National Guard and opened storm shelters sufficient to house up to 62,000 people.
A US aircraft carrier with a field hospital and dozens of aircraft able to conduct rescue or supply missions have been put on standby, US emergency authorities said.