Hurricane Ian slammed into the southwest Florida coast on Wednesday as a Category 4 monster storm, with strong winds and torrential rain threatening “catastrophic” damage and flooding.

The National Hurricane Center (NHC) said the eye of the “extremely dangerous” hurricane made landfall on the offshore island of Cayo Costa west of the city of Fort Myers just after 3:00 p.m. (1900 GMT).

Dramatic television footage from the coastal city of Naples showed floodwaters pouring into beachfront homes, flooding streets and sweeping away vehicles.

Some neighborhoods in Fort Myers, which has a population of more than 80,000, resemble lakes.

The NHC said Ian was gripping maximum sustained winds of 150 miles per hour when he landed and forecast “catastrophic storm surges, winds and flooding in the Florida Peninsula.”

Florida Gov. Ron DeSantis said Wednesday that more than 1.1 million power outages have been reported in the state and that the number is expected to increase.

Ian is expected to strike several million people across Florida and the southeastern states of Georgia and South Carolina, and may have caused multiple offshore casualties.

The US border patrol said 20 migrants were missing after their boat sank. Four surviving Cubans swam to shore in the Florida Keys and three were rescued at sea by the Coast Guard.

As hurricane conditions unfolded, forecasters warned of a once-in-a-generation catastrophe.

“This will be a storm that we will be talking about for many years to come,” said Ken Graham, director of the National Weather Service. “It’s a historic event.”

DeSantis said the state is going to have a “bad, bad day, two days.”

In Punta Gorda, north of Fort Myers, the streets emptied as howling winds tore fronds from palm trees and rattled power poles.

About 2.5 million people were under mandatory evacuation orders in a dozen coastal Florida counties, with several dozen temporary shelters set up and voluntary evacuations recommended in others.

For those who decided to weather the storm, authorities stressed that it was too late to flee and residents should huddle together and stay indoors.

Tampa and Orlando airports grounded all commercial flights and cruise lines delayed departures or canceled trips.

With up to 61 centimeters of rain falling on parts of the so-called Sunshine State and a storm surge that could reach devastating heights of 3.6 to 5.5 meters, authorities warned of disaster emergency conditions.

“This is a life-threatening situation,” the NHC warned.

The storm was expected to be moving across central Florida before emerging in the Atlantic late Thursday.

Ian had plunged all of Cuba into darkness a day earlier after hitting the west of the country as a Category 3 storm, crippling the island’s power grid.

“Devastation and Destruction. These are terrible hours. There’s nothing left here,” a 70-year-old resident of the western city of Pinar del Rio was quoted as saying in a social media post by his journalist son, Lazaro Manuel Alonso.

At least two people died in Pinar del Rio province, Cuban state media reported.

In the United States, according to the Pentagon, 3,200 National Guardsmen have been called up in Florida, with another 1,800 on the way.

DeSantis said state and federal emergency responders would be dedicating thousands of workers to help manage the storm response.

“There will be thousands of Floridians who will need help rebuilding,” he said.

As climate change warms the sea surface, the number of strong tropical storms, or cyclones with stronger winds and more precipitation, is likely to increase.

However, the total number of cyclones may not.

According to Gary Lackmann, a professor of atmospheric sciences at North Carolina State University, studies have also identified a possible link between climate change and rapid intensification — when a relatively weak tropical storm becomes a Category 3 or higher hurricane within a 24-hour period, such as it happened to Ian.

“The consensus remains that there will be fewer storms, but that the strongest will get stronger,” Lackmann told the AFP news agency.