PORT-AU-PRINCE, Haiti -- Hurricane Irma battered the Turks and Caicos Islands early Friday and Cuba evacuated tourists from beachside resorts as the fearsome storm continued a rampage through the Caribbean that has killed at least 16 people, with Florida in its sights.

Waves as high as 20 feet were expected in the Turks and Caicos. Communications went down as the storm slammed into the islands, and the extent of the devastation was unclear.

The first hurricane warnings were issued for parts of southern Florida as the state braced for what could be a catastrophic hit over the weekend. Following in Irma's wake was Hurricane Jose, with some of the islands hit hardest by Irma in its expected path.

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Irma weakened to a still-powerful Category 4 storm early Friday. The U.S. National Hurricane Center said Irma's maximum sustained winds decreased to about 150 mph. The center said some fluctuations in strength are likely over the next day or two, but Irma is expected to stay a Category 4 storm.

At 8 a.m. ET Friday, the hurricane's center was about 80 miles northeast of Cabo Lucrecia, Cuba, and about 450 miles southeast of Miami and was moving west-northwest at 16 mph.

On the forecast track, the hurricane center said, Irma's eye should continue to move westward, away from the Turks and Caicos Islands, toward the southeastern Bahamas Friday morning. The storm's core will then move between the northern coast of Cuba and the Bahamas Friday or Saturday, and be near the Florida Keys and southern Florida Peninsula Sunday morning.

Hurricane Irma's projected path as of 5 a.m. EDT on September 8, 2017 National Hurricane Center

Florida prepared for Irma's wrath, with people rushing to board up their homes, take their boats out of the water and gas up their cars. With gasoline running out and tensions rising, the Florida Highway Patrol escorted tanker trucks sent to replenish gas stations.

"It is wider than our entire state and could cause major and life-threatening impacts from coast to coast. Regardless of which coast you live on, be prepared to evacuate," Florida Gov. Rick Scott said.

Forecasters warned Irma could slam headlong into the Miami metropolitan area of 6 million people and punish the entire length of the state's Atlantic coast before moving into Georgia and South Carolina.

More than a half-million people in Miami-Dade County were ordered to leave as Irma closed in.

"Take it seriously, because this is the real deal," said Maj. Jeremy DeHart, a U.S. Air Force Reserve weather officer who flew through the eye of Irma at 10,000 feet.

The U.S. Consulate General in Curacao said it believes about 6,000 Americans are stranded on St. Martin. It said it was working with the U.S. and other governments to try to figure out how to get the Americans off the island either by air or boat. Frantic Americans were calling home to relatives to try to get them off the island ahead of Hurricane Jose, which had some of the islands hit hardest by Irma in its expected path.

French, British and Dutch military authorities rushed aid to a devastated string of Caribbean islands where thousands were homeless. Warships and planes were sent with food, water and troops after the hurricane smashed homes, schools and roads, laying waste to some of the world's most beautiful and exclusive tourist destinations.

Dutch King Willem-Alexander will fly to the Caribbean island of Curacao on Sunday to inspect the coordination of relief efforts for devastated former colony St. Maarten in the aftermath of Hurricane Irma, which hit as a Category 5 storm. The Royal House announced the visit Friday.

The first islands hit by the storm were scenes of terrible destruction.

French Interior Minister Gerard Collomb said Irma left at least nine people dead, seven missing and 112 injured on the French Caribbean islands of St. Martin and St. Barts. Collomb told reporters Friday the casualty toll could rise as more emergency workers reach deeper into the area.

That raises Irma's unofficial death toll to at least 16.

Homes were splintered and road signs scattered by the fierce winds on the French side of St. Martin, an island split between Dutch and French control. The cafes and clothing shops of the picturesque seaside village of Marigot were submerged in brown floodwaters. The toll could rise because rescue teams had yet to get a complete look at the damage.

Looting was reported in St. Martin. Annick Girardin, minister for France's overseas territories, described on BFM television Friday "scenes of pillaging" of televisions as well as food and water. She lamented "how people can take advantage of the distress of others" and said it's essential for police to restore order and ensure urgent care for victims.

At least four people were killed in the U.S. Virgin Islands, and officials said they expected to find more bodies. Authorities described the damage as catastrophic and said crews were struggling to reopen roads and restore power.

Three more deaths were reported on the British island of Anguilla, as well as Barbuda and the Dutch side of St. Martin.

Irma also slammed the French island of St. Barts, tearing off roofs and knocking out electricity in the high-end tourist destination.

French Interior Minister Gerard Collomb said 100,000 food rations were sent to St. Barts and St. Martin, the equivalent of four days of supplies.

Dutch Prime Minister Mark Rutte said the storm "caused wide-scale destruction of infrastructure, houses and businesses."

"There is no power, no gasoline, no running water. Houses are under water, cars are floating through the streets, inhabitants are sitting in the dark in ruined houses and are cut off from the outside world," he said.

Big waves smashed a dozen homes into rubble in the Dominican fishing community of Nagua, but work crews said all the residents had left before the storm. Officials said 11,200 people in all had evacuated vulnerable areas, while 55,000 soldiers had been deployed to help the cleanup.

In Haiti, two people were injured by a falling tree, a national roadway was blocked by debris and roofs were torn from houses along the northern coast but there were no immediate reports of deaths. Officials warned that could change as Irma continued to lash Haiti, where deforested hillsides are prone to devastating mudslides that have wiped out entire neighborhoods of precariously built homes in flood zones.

"We are vulnerable. We don't have any equipment to help the population," Josue Alusma, mayor of the northern city of Port de Paix, said on Radio Zenith FM.

Farther out in the Atlantic, Hurricane Jose strengthened into a Category 3 storm with 125 mph winds and posed a potential threat for Saturday to some of the same islands ravaged by Irma.

French President Emmanuel Macron's office said he would go to the islands as soon as the weather permits it. Saying he was "grief-stricken," Macron called for concerted efforts to tackle global warming to prevent similar natural disasters.

Two Dutch navy ships were in St. Martin with vital supplies. And two Dutch military aircraft were being sent to the island of Curacao and on to St. Martin to deliver food and water intended to last the population of 40,000 five days. The aircraft were carrying 100 extra troops to deliver aid, repair infrastructure and restore order.

Britain was sending hundreds of troops and the Royal Navy flagship HMS Ocean to Anguilla, Montserrat and the British Virgin Islands.

In Anguilla, officials reported extensive damage to the airport, hospitals, shelters and schools and said 90 percent of roads were impassable.

On Barbuda, nearly every building was damaged when the hurricane's core crossed almost directly over the island early Wednesday. About 60 percent of its roughly 1,400 residents were left homeless, Antigua and Barbuda Prime Minister Gaston Browne said.

He said roads and telecommunications systems were wrecked and recovery will take months, if not years.

"It is just really a horrendous situation," Browne said.