San Juan— Hurricane Irma slammed across islands in the Caribbean on Wednesday, packing a potentially catastrophic mix of pounding winds, raging surf and rain en route to a possible Florida landfall at the weekend.
Irma is expected to become the second powerful storm to thrash the US mainland in as many weeks but its precise trajectory was uncertain. Hurricane Harvey killed more than 60 people and caused as much as $180bn in damage after hitting Texas late in August.
The eye of Irma, a category 5 storm with winds of 295km/h, passed over the island of St Martin, east of the US territory of Puerto Rico, on Wednesday, the National Hurricane Centre (NHC) in Miami said. Category 5 is its highest.
In Puerto Rico’s capital of San Juan, a handful of people stood on the wind-whipped shore of a beachfront park on Wednesday morning to take a last look at the ocean before seeking shelter.
"I am worried. This is going to be a huge storm, bigger than I have ever seen," said Angelica Flecha. She has stocked her second-floor home with food and water and put metal storm shutters on the windows, but was worried about a storm surge on the island, which is under hurricane warning.
Most businesses were closed and streets were almost empty.
Cars packed parking lots of stores that were still open, with shoppers stuffing ice and water into their trunks.
Puerto Rico’s governor, Ricardo Rossello, urged the island’s 3.4-million residents to seek refuge in one of 460 hurricane shelters.
Two US tourists in the French territory of Guadeloupe, Loren Ann Mayo and Rachel Scharett, told CNN they were weathering the storm in their hotel room’s bathroom. Following a loud cracking noise, Mayo said, "The balcony snapped and is now hanging on by one little piece of wire."
Emergency officials on Antigua and Barbuda reported three injuries but minimal damage, with some roofs blown off.
Communications between the islands were cut off.
Several other parts of the Leeward Islands, including Anguilla, Montserrat, St Kitts and Nevis, as well as the US and British Virgin Islands and the Dominican Republic were under hurricane warning.
In Paris, the French government said it had delivered water and food to two of its overseas territories, St Martin and St Barthelemy, and that emergency response teams would be sent once the storm had passed.
French Interior Minister Gerard Collomb said at least four buildings were damaged and low-lying regions had been flooded. "For now we’re not aware of any deaths," Collomb told reporters in Paris.
French Overseas Territories Minister Annick Girardin said "there was much to fear" for citizens who had not heeded calls to seek safety in buildings that were more secure.
Irma ranked as one of the five most powerful Atlantic hurricanes in the past 80 years.
US President Donald Trump tweeted that he was monitoring the storm closely. He approved emergency declarations for Florida, Puerto Rico and the US Virgin Islands, mobilising federal disaster relief efforts, the White House said.
Authorities in the Florida Keys ordered a mandatory evacuation of visitors to start at sunrise on Wednesday and public schools in South Florida were ordered closed.
Residents of low-lying areas in densely populated Miami-Dade County were urged to move to higher ground.
Florida governor Rick Scott said there would be more mandatory evacuations around the state as Irma approached and as surges were expected to reach 3m. "We can rebuild your home, we can’t rebuild your life," Scott said on ABC’s Good Morning America.
Irma could be worse than Hurricane Andrew, which devastated the state in 1992.
Residents of Texas and Louisiana were still recovering from Harvey, which struck Texas as a category 4 hurricane on August 25.
It dumped several metres of rain, destroying thousands of homes and businesses, and displaced more than 1-million people.