PANAMA CITY, United States (AFP) — Michael weakened to a tropical storm Thursday after wreaking havoc along Florida’s Gulf Coast, flooding homes and streets, ripping away roofs and snapping trees and power lines as it roared ashore as a raging Category 4 hurricane.

Two deaths were blamed on the hurricane — one in Florida and one in Georgia as the storm raced across the neighbouring state, heading northeast.

Florida officials said Michael, packing winds of 155 miles per hour (250 kilometres per hour), was the most powerful storm to hit the state’s Panhandle area since record-keeping began more than a century ago. It was also one of the most powerful hurricanes ever to hit the United States.

Michael remained dangerous even though it weakened over the course of Wednesday afternoon and evening.

Around midnight (0400 GMT Thursday) it was downgraded to a tropical storm as it barrelled across central Georgia, still dumping torrential rain and packing 60 mph winds. These eased steadily overnight, to 50 mph just before dawn.

On its current track the storm is headed for the Carolinas, where cities and towns are still recovering from Hurricane Florence last month.

In Florida, pictures and video from Mexico Beach — a community of about 1,000 people where Michael made landfall around midday Wednesday — showed scenes of devastation, with houses floating in flooded streets, some ripped from their foundations and missing roofs.

Roads were filled with piles of floating debris.

After being battered for nearly three hours by strong winds and heavy rains, roads in PanamaCity were virtually impassable and trees, satellite dishes and traffic lights lay in the streets.

Nearly 370,000 people were left without power, mostly in Florida, but also Alabama and Georgia, news reports said.

Briefing President Donald Trump at the White House, Federal Emergency Management Agency (FEMA) chief Brock Long said Michael was the most intense hurricane to strike the Florida Panhandle since record keeping began in 1851.

“Along our coast, communities are going to see unimaginable devastation,” Scott said, with storm surge posing the greatest danger.

“Water will come miles in shore and could easily rise over the roofs of houses,” he said.

At a midterm election rally in Pennsylvania on Wednesday night, Trump offered his “thoughts and prayers” to those in the path of the storm and said he would be visiting Florida soon.

“I’ll be travelling to Florida very, very shortly and I just want to wish them all the best. Godspeed,” Trump said.

Hundreds of thousands of people were ordered to evacuate their homes and the governor told residents who had not done so to “hunker down and be careful.”

Ken Graham, director of the Miami-based National Hurricane Center, said Michael was “unfortunately, a historical and incredibly dangerous and life-threatening situation.”

– Just shy of Category 5 –

Olivia Smith, public information officer for the Gadsden County Board of County Commissioners, said there was one hurricane-related fatality, adding that the incident was “debris-related. There was a tree involved.”

Smith could not provide details on the victim.

In Georgia, an 11-year-old girl died when a car port flipped into the air by a gust of wind landed on her home, Travis Brooks, head of the emergency relief agency in Seminole County, told AFP.

General Terrence O’Shaughnessy, commander of the North American Aerospace Defense Command, said some Florida residents may have been surprised by the rapid growth of the storm.

“It really started as a tropical storm, and then it went to Category 1, then it was Category 2 and before you know it, it was Category 4,” O’Shaughnessy said.

The NHC said tropical storm Michael will continue to move northeast toward the Carolinas — as of 0900 GMT the eye was in eastern Georgia — until it moves off the mid-Atlantic coast by early Friday.

The agency warned of possible flash flooding Thursday in parts of Georgia, the Carolinas and southeastern Virginia because of heavy rains from Michael.

Long, the head of FEMA, said many Florida buildings were not built to withstand a storm above the strength of a Category 3 hurricane on the five-level Saffir-Simpson Hurricane Wind Scale.

As it came ashore, Michael was just shy of a Category 5 — defined as a storm packing top sustained wind speeds of 157 mph or above.

– Emergency declaration –

An estimated 375,000 people in more than 20 counties were ordered or advised to evacuate.

Trump issued an emergency declaration for Florida, freeing up federal funds for relief operations and providing the assistance of FEMA, which has more than 3,000 people on the ground.

State officials issued disaster declarations in Alabama and Georgia and the storm is also expected to bring heavy rainfall to North and South Carolina.

The Carolinas are still recovering from Hurricane Florence, which left dozens dead and is estimated to have caused billions of dollars in damage last month.

It made landfall on the coast as a Category 1 hurricane on September 14 and drenched some parts of the state with 40 inches (101 centimetres) of rain.

Last year saw a string of catastrophic storms batter the western Atlantic — including Irma, Maria and Harvey, which caused a record-equalling $125 billion in damage when it flooded the Houston metropolitan area.

Scientists have long warned that global warming will make storms more destructive, and some say the evidence for this may already be visible.