Extremely powerful Hurricane Michael crashed into the Florida’s northwestern Panhandle coast on Wednesday, flooding towns and ripping up trees with 155 mile per hour(249 kph) winds and the potential for a devastating storm surge.

Michael, which had caught many by surprise with its rapid intensification as it churned north over the Gulf of Mexico, was the most powerful storm ever recorded to hit the Panhandle, and it strengthened even as it approached land.

It made landfall northwest of the town of Mexico Beach early on Wednesday afternoon as a Category 4 hurricane on the five-step Saffir-Simpson scale, just shy of an extremely rare Category 5.

The storm, which caused a major disruption for oil and gas production in the U.S. Gulf of Mexico, had the potential to drive sea water levels as high as 14 feet (4.3 meters) above normal in some areas, the National Hurricane Center said.

“My God it’s scary. I didn’t expect all this,” said Bill Manning, 63, a grocery clerk who left his camper van in Panama City, Florida, to move into a hotel where the power was already out.

“Panama City, I don’t know if there will be much left.”

People in coastal parts of 20 Florida counties had been told to leave their homes but by Wednesday morning were told it was too late to flee. Much of the affected area is rural and known for small tourist cities, beaches and wildlife reserves, as well as the state capital, Tallahassee.

Even before Michael made full landfall, it was whipping trees with its winds and had caused flooding in the town of Apalachicola, where more than five feet (1.5 meters) of water was reported, and in Port St. Joe.

“It feels like you don’t know when the next tree is going to fall on top of you because its blowing so ferociously,” said Port St. Joe Mayor Bo Patterson. “You just don’t know when the next one is going down. It’s very, very scary. We have trees being uprooted, heavy, heavy rain.”

Patterson said about 2,500 of the town’s 3,500 people were still there, including about 100 in a beachside area who did not follow a mandatory evacuation order. The two bridges leading out of Port St. Joe were closed, meaning no one could get out now.

“This happened so quickly, we weren’t exactly prepared,” he said.

Brock Long, head of the Federal Emergency Management Agency, said early evacuation efforts in the area were slow.

Michael grew from a tropical storm to a Category 4 hurricane in about 40 hours.

“Satellite images of Michael’s evolution on Tuesday night were, in a word, jaw-dropping,” wrote Bob Henson, a meteorologist with weather site Weather Underground.

Hurricane center Director Ken Graham said on Facebook that Michael would be the worst storm in recorded history to hit the Panhandle.

“Going back through records to 1851 we can’t find another Cat 4 in this area, so this is unfortunately a historical and incredibly dangerous and life-threatening situation,” he said.

About 43,000 homes and businesses customers were already without power around midday.

At 2 p.m. ETD (1800 GMT), the center of the storm was a few miles northwest of Mexico Beach and about 20 miles (30 km) southeast of Panama City. Michael was heading north-northeast at 14 mph (22 kph) with maximum sustained winds of 155 mph (250 kph), the hurricane center said.

More than 40 percent of daily crude oil production and more than one-third of natural gas output was lost from offshore U.S. Gulf of Mexico wells on Wednesday because of platform evacuations and shut-ins caused by Michael.

President Donald Trump declared a state of emergency for the entire state of Florida, freeing up federal assistance to supplement state and local disaster responses. He was briefed by Long in the Oval Office on preparations.