Caibarién, Cuba (CNN) Packing life-threatening winds, provoking massive storm surge and causing a host of rainfall dangers, Hurricane Irma slammed northern Cuba on Saturday, continuing to plod a path of devastation through the Caribbean en route to the US state of Florida .

A string of small Caribbean islands was left reeling by the massive hurricane, which strengthened to a Category 5 storm as it made landfall overnight in Cuba. It was downgraded late Saturday morning to Category 3 but was expected to regain power.

"Irma is forecast to restrengthen once it moves away from Cuba, and ... to remain a powerful hurricane as it approaches Florida," the US National Hurricane Center said Saturday evening.

In its 8 p.m. ET advisory, the National Hurricane Center reported that Irma had temporarily slowed down, moving toward Florida near 7 mph (11kph). The storm is about 110 miles (175 kilometers) southeast of Key West and is expected to reach the Florida Keys early Sunday. The hurricane is expected to move along or near the southwest coast of Florida Sunday afternoon.

Irma slams into Cuba, some towns on north coast underwater. pic.twitter.com/3ceY2fjlKp

At least 24 people were known to have died in the Caribbean as a result of Irma. Many islands were still assessing the damage, even as they prepared for the arrival of another major storm, Hurricane Jose.

A hurricane warning for Barbuda and Anguilla was downgraded to a tropical storm warning on Saturday morning and later discontinued. Tropical storm warnings remain in place for St. Martin and St. Barts.

By Saturday evening, the enter of Irma lingered near the north coast of Cuba, packing sustained winds near 120 mph (195 kph) with higher gusts. Hurricane-force winds extend outward up to 70 miles (110 kilometers) from the center, and tropical-storm-force winds extend outward up to 195 miles (315 kilometers).

Irma's blinding rain and powerful winds began pummeling Caibarién, Cuba, late Friday as the outer bands of the massive storm made their entrance, knocking out power in a town that normally would be busy with tourists.

By dawn Saturday, the town's main street had waves rolling down it, and within hours the whole town was flooded with several feet of water. Roofs could be seen flying off and trees were blown down as the wind gusted and roared. Officials reported a wind gust of 124 mph (200 kph) around midmorning Saturday.

Irma has submerged the town of Caibarien, Cuba under several feet of water. pic.twitter.com/qz4QwNdYak — Patrick Oppmann CNN (@CNN_Oppmann) September 9, 2017

Most people in the coastal area live in one-story homes, putting them at great risk as floodwaters rose to roof level in some places. Residents were overwhelmed by the damage and said recovery will take time.

Many people had left town over the past couple of days, with all foreigners urged to evacuate. Those who remained were prepared, though they knew this was a storm like few had ever experienced, they told CNN.

The Cuban government staged emergency supplies and building equipment ahead of the storm's arrival, but it could be some time before the extent of the damage is known.

A woman and child use a blanket as protection from wind and rain as they walk Friday in Caibarien, Cuba.

Gusts destroy wind-measuring instrument

As of 8 p.m. ET Saturday, a hurricane warning for Irma remained in place for the Cuban provinces of Camaguey, Ciego de Avila, Sancti Spiritus, Villa Clara, Matanzas, and Havana -- as well as for the northwestern Bahamas. According to state-run news organization Granma, there are 14,500 foreign tourists riding out Irma in the resort town of Varadero in the Matanzas province.

Irma struck the archipelago north of Cuba's Camaguey and Ciego de Avila provinces with gusts so strong they destroyed an instrument used to measure wind, Cuba's meteorological agency reported.

Hurricane-strength winds later were recorded in the northern half of Camaguey province, the agency said.

As Irma advanced over neighboring Ciego de Avila province, 16- to 23-foot waves (5 to 7 meters) were recorded. As the storm headed westward, the possibility of even bigger waves and greater flooding was high along the northern Cuban coast, including in Havana, the agency said.

Irma was the first Category 5 hurricane to hit Camaguey in 85 years, according to the province's state media radio station.

Damage was reported in all municipalities in Camaguey, the station said, mostly in the form of torn-off roofs, damage to buildings, downed trees and loss of electricity.

Photos: Hurricane Irma tears through Caribbean Carmelo Mota, a builder, searches for tools in his destroyed home in Charlotte Amalie, US Virgin Islands, on Monday, September 18. Hurricane Irma devastated the US territory and other Caribbean islands in the region, leaving them exposed to new storms brewing in the Atlantic. Hide Caption 1 of 55 Photos: Hurricane Irma tears through Caribbean An aerial photo shows the devastation in Road Town, the capital of Tortola, the largest and most populated of the British Virgin Islands, on Wednesday, September 13. Hide Caption 2 of 55 Photos: Hurricane Irma tears through Caribbean UK Foreign Secretary Boris Johnson talks to a resident of Anguilla during a visit on September 13. Hide Caption 3 of 55 Photos: Hurricane Irma tears through Caribbean People collect food that was delivered by emergency workers in the Sandy Ground area of Marigot, St. Martin, on Tuesday, September 12. Hide Caption 4 of 55 Photos: Hurricane Irma tears through Caribbean Buildings are destroyed in St. Martin on September 12. Hide Caption 5 of 55 Photos: Hurricane Irma tears through Caribbean French President Emmanuel Macron shakes hands with St. Martin residents during a visit to the island on September 12. Hide Caption 6 of 55 Photos: Hurricane Irma tears through Caribbean French soldiers patrol St. Martin on September 12. Hide Caption 7 of 55 Photos: Hurricane Irma tears through Caribbean A person works to clean up a street September 12 after Hurricane Irma flooded parts of Havana, Cuba. Hide Caption 8 of 55 Photos: Hurricane Irma tears through Caribbean A man makes repairs in Havana on September 12. Hide Caption 9 of 55 Photos: Hurricane Irma tears through Caribbean This Marigot church was among the buildings destroyed in the storm. Hide Caption 10 of 55 Photos: Hurricane Irma tears through Caribbean Cubans affected by Hurricane Irma line up to collect drinking water in Isabela de Sagua, Cuba, on Monday, September 11. Hide Caption 11 of 55 Photos: Hurricane Irma tears through Caribbean Dutch King Willem-Alexander, front right, tours damage in St. Maarten on September 11. Hide Caption 12 of 55 Photos: Hurricane Irma tears through Caribbean A palm tree sticks out of a pool on the French side of St. Martin on September 11. Hide Caption 13 of 55 Photos: Hurricane Irma tears through Caribbean A woman stands next to her water-logged belongings that had been laid out to dry in front of her home in Isabela de Sagua on September 11. Hide Caption 14 of 55 Photos: Hurricane Irma tears through Caribbean People line up for supplies in St. Martin on September 11. Hide Caption 15 of 55 Photos: Hurricane Irma tears through Caribbean The skeleton of a boat drifts in St. Martin's Simpson Bay on September 11. Hide Caption 16 of 55 Photos: Hurricane Irma tears through Caribbean People salvage material from the remains of a house in Isabela de Sagua on September 11. Hide Caption 17 of 55 Photos: Hurricane Irma tears through Caribbean Members of the British Army provide support on Tortola, one of the British Virgin Islands. Hide Caption 18 of 55 Photos: Hurricane Irma tears through Caribbean A woman carries a dog at an airport checkpoint in St. Martin on September 11. Hide Caption 19 of 55 Photos: Hurricane Irma tears through Caribbean People wade through a flooded street as a wave crashes in Havana on Sunday, September 10. Hide Caption 20 of 55 Photos: Hurricane Irma tears through Caribbean Two men search through the rubble of their St. Martin restaurant on September 10. Hide Caption 21 of 55 Photos: Hurricane Irma tears through Caribbean People make their way through debris in the Cojimar neighborhood of Havana on September 10. Hide Caption 22 of 55 Photos: Hurricane Irma tears through Caribbean People board a plane leaving St. Martin on September 10. Hide Caption 23 of 55 Photos: Hurricane Irma tears through Caribbean A man wades through a flooded street in Havana on September 10. Hide Caption 24 of 55 Photos: Hurricane Irma tears through Caribbean An overview of Havana shows flooded streets on Saturday, September 9. Hide Caption 25 of 55 Photos: Hurricane Irma tears through Caribbean A woman surveys flooding in Havana on September 9. Hide Caption 26 of 55 Photos: Hurricane Irma tears through Caribbean A boat rests in a cemetery after Irma tore through Marigot, St. Martin. Hide Caption 27 of 55 Photos: Hurricane Irma tears through Caribbean Residents return home after Irma passed through Caibarien, Cuba, on September 9. Hide Caption 28 of 55 Photos: Hurricane Irma tears through Caribbean A man walks in Caibarien on September 9. Hide Caption 29 of 55 Photos: Hurricane Irma tears through Caribbean A man carries a child through a flooded street in Fort-Liberte, Haiti, on Friday, September 8. Hide Caption 30 of 55 Photos: Hurricane Irma tears through Caribbean A man walks on a St. Martin street covered in debris on September 8. Hide Caption 31 of 55 Photos: Hurricane Irma tears through Caribbean A damaged home is tilted onto its side on the Puerto Rican island of Culebra on Thursday, September 7. Hide Caption 32 of 55 Photos: Hurricane Irma tears through Caribbean A home is surrounded by debris in Nagua, Dominican Republic, on September 7. Hide Caption 33 of 55 Photos: Hurricane Irma tears through Caribbean Irma damage is seen in St. Martin's Orient Bay on September 7. Hide Caption 34 of 55 Photos: Hurricane Irma tears through Caribbean Employees from an electrical company work to clear a fallen tree in Sanchez, Dominican Republic. Hide Caption 35 of 55 Photos: Hurricane Irma tears through Caribbean A woman makes her way through debris in Fajardo, Puerto Rico, on September 7. Hide Caption 36 of 55 Photos: Hurricane Irma tears through Caribbean In this image made from video, damaged houses are seen in St. Thomas on September 7. Hide Caption 37 of 55 Photos: Hurricane Irma tears through Caribbean The storm left widespread destruction on the island of Barbuda on September 7. Hide Caption 38 of 55 Photos: Hurricane Irma tears through Caribbean A flattened home is seen in Nagua, Dominican Republic, on September 7. Hide Caption 39 of 55 Photos: Hurricane Irma tears through Caribbean Nagua residents ride through an area affected by the storm on September 7. Hide Caption 40 of 55 Photos: Hurricane Irma tears through Caribbean Trash and debris is washed ashore in Cap-Haitien, Haiti, on September 7. Hide Caption 41 of 55 Photos: Hurricane Irma tears through Caribbean People walk through damage in Marigot, St. Martin, on September 7. Hide Caption 42 of 55 Photos: Hurricane Irma tears through Caribbean People survey damage in Marigot on September 7. Hide Caption 43 of 55 Photos: Hurricane Irma tears through Caribbean Bluebeard's Castle, a resort in St. Thomas, was hit hard by Irma. St. Thomas resident David Velez sent this photo to CNN on September 7. Hide Caption 44 of 55 Photos: Hurricane Irma tears through Caribbean Irma ruined these vehicles in St. Thomas. Hide Caption 45 of 55 Photos: Hurricane Irma tears through Caribbean Waves smash into St. Martin on Wednesday, September 6. Hide Caption 46 of 55 Photos: Hurricane Irma tears through Caribbean A man looks at a vehicle turned upside down in the British territory of Anguilla. Hide Caption 47 of 55 Photos: Hurricane Irma tears through Caribbean An aerial view of St. Martin on September 6. Hide Caption 48 of 55 Photos: Hurricane Irma tears through Caribbean Damaged cars are seen on a St. Martin beach on September 6. Hide Caption 49 of 55 Photos: Hurricane Irma tears through Caribbean A boat is washed onto shore in St. Martin. Hide Caption 50 of 55 Photos: Hurricane Irma tears through Caribbean Cars are piled up in Marigot on September 6. Hide Caption 51 of 55 Photos: Hurricane Irma tears through Caribbean A man walks past damaged buildings in St. Martin on September 6. Hide Caption 52 of 55 Photos: Hurricane Irma tears through Caribbean A car is flipped onto its side in Marigot. Hide Caption 53 of 55 Photos: Hurricane Irma tears through Caribbean Broken palm trees are scattered on a Marigot beach on September 6. Hide Caption 54 of 55 Photos: Hurricane Irma tears through Caribbean Irma floods a beach in Marigot on September 6. Hide Caption 55 of 55

Irma's eye was due to strike part of the Florida Keys on Sunday morning before driving up the state's southwestern coast by Sunday afternoon, according to the hurricane center.

Forecasters and Florida officials issued dire warnings urging residents in Irma's path to evacuate immediately. About 6.3 million people in the state had been ordered to leave, officials said.

Devastation left in Irma's wake

Of the 24 deaths blamed on Irma in the Caribbean, nine were in unspecified French territories, one in Barbuda, one in Anguilla, two in Dutch-administered St. Maarten, four in the British Virgin Islands, four in the US Virgin Islands, and three in Puerto Rico.

The tiny island of Barbuda was perhaps worst hit so far by Irma , with Prime Minister Gaston Browne describing the result as "total devastation."

"I have never seen any such destruction on a per capita basis compared to what I saw in Barbuda this afternoon," Browne told CNN on Wednesday.

Antigua, Barbuda's sister island and home to about 80,000 people, was spared the brunt of the storm. Many residents there have been evacuated ahead of Jose.

"There is a sense of dread ... utility poles are down everywhere. There is no power and no public water and it appears it may take a long time to restore," Xaverius van der Hoek, who lives in St. Maarten, told CNN.

A man and a boy take a look at the damage Irma brought on September 7, in Marigot, near the Bay of Nettle, on the island of St. Martin.

Looting broke out on the island, home to about 72,000 people, and security forces were deployed to deal with the problem, French and Dutch authorities said Friday.

Irma caused roughly €1.2 billion ($1.44 billion) of insured damage in the French portion of St. Martin and in St. Barts, French state-owned insurer CCR said Saturday.

"This amount covers damages to homes, vehicles and businesses (including operating losses) that are covered by the natural disaster compensation scheme," CCR said.

State of emergency declared

Just to the north, Anguilla, a 90-square kilometer island that is among several British overseas territories in the Caribbean, "received the hurricane's full blast," according to UK Foreign and Commonwealth Office Minister Alan Duncan.

The US and British Virgin Islands were also pummeled by Irma. Pictures from St. Thomas, the most populated of the US Virgin Islands and a popular tourist destination, showed extensive damage.

Wreckage in Irma's wake is seen Wednesday on St. Thomas, a tourist destination in the US Virgin Islands.

"All of us have been affected by Irma and some more than others," Gus Jaspert, governor of the British Virgin Islands, said in a Facebook statement late Thursday in which he declared a state of emergency for the territory.

"Apart from the structural damage, there have sadly been reports of casualties and fatalities," he said. "I am truly heartbroken by this news."

First responders check an empty car caught in floodwaters Wednesday in Fajardo, Puerto Rico.

Puerto Rico, an unincorporated US territory, managed to avoid a direct hit from Irma but suffered strong winds and torrential rains. Hundreds of thousands of people remained without power on Friday.

Strong winds and heavy rain also lashed the Dominican Republic, Haiti and the low-lying Turks and Caicos Islands Thursday into Friday. The Turks and Caicos' capital island of Grand Turk suffered "quite a bit of damage," including to part of a hospital's roof, Gov. John Freeman told CNN on Friday.