Search and rescue teams are trying to help survivors after Hurricane Michael wreaked “unimaginable destruction” on parts of Florida.

Thousands of houses were destroyed by the third-most powerful hurricane on record to hit the continental US.

At least two deaths were blamed on Michael, and though weakened into a tropical storm, it continued to bring heavy rain and blustery winds to the south east as it pushed inland.

Under a blue sky, Florida families emerged tentatively from darkened shelters and hotels to a landscape of shattered homes and shopping centres.

Over 900,000 homes and businesses in Florida, Alabama, Georgia and the Carolinas were without power.

“This morning, Florida’s Gulf Coast and Panhandle and the Big Bend are waking up to unimaginable destruction,” Governor Rick Scott said. “So many lives have been changed forever. So many families have lost everything. … This hurricane was an absolute monster.”

But the full extent of the damage was only slowly becoming clear, with some of the worst areas difficult to reach. An 80-mile stretch of Interstate 10, the main east-west route along the Panhandle, was closed because of debris.

One of the hardest-hit spots was Mexico Beach, where Michael crashed ashore as a Category 4 monster with 155mph winds. Video from a CNN helicopter revealed widespread devastation across the town of about 1,000 people.

Entire blocks of homes near the beach were washed away, leaving nothing but concrete slabs in the sand. Rows and rows of other homes were reduced to piles of debris or crumpled and slumped at odd angles.

Mr Scott said the National Guard got into Mexico Beach and rescued 20 people who survived the direct hit. The town was under a mandatory evacuation order as the rapidly developing storm closed in but some people were determined to ride it out.

Tropical Weather
Haley Nelson inspects damage to her home in Panama City (Pedro Portal/AP)

A day later, the beach town remained difficult to reach by land, with roads covered by fallen trees, power lines and other debris.

The governor pleaded with people in Florida not to go home yet.

“I know you just want to go home. You want to check on things, and begin the recovery process,” Mr Scott said, but “we have to make sure things are safe”.

Meanwhile, the Coast Guard said it rescued at least 27 people, mostly from homes damaged along the Florida coastline, and searched for more victims.

Among those brought to safety were nine people rescued by helicopter from a bathroom of their Panama City home after their roof collapsed.

Tropical Weather
Hurricane Michael slammed into the Florida Panhandle with winds of 155 mph (Douglas R Clifford/Tampa Bay Times via AP)

Florida officials also said they were moving patients from damaged health care facilities.

Along the 200-mile Panhandle, Michael washed away white-sand beaches, hammered military bases and destroyed coastal communities, stripping trees to stalks, shredding roofs, toppling trucks and pushing boats into buildings.

Authorities said a falling tree killed a man outside Tallahassee, Florida, and an 11-year-old girl in Georgia was killed when the wind picked up a carport and dropped it on her home. One of the carport’s legs punctured the roof and hit her on the head.

An Associated Press team drove for miles and encountered extensive destruction around Panama City. Though most homes were still standing, no property was left undamaged.

Downed power lines lay nearly everywhere and roofs had been peeled away and sent airborne.

Hundreds of cars had broken windows and twisted street signs lay on the ground. Pine trees were stripped and snapped off about 20ft high.

Tropical Weather
John Gouge walks through flood water after Hurricane Michael (Chris O’Meara/AP)

More than 375,000 people up and down the Gulf Coast were ordered or urged to evacuate as Michael closed in. But it moved so fast and intensified so quickly that people did not have much time to prepare, and emergency authorities lamented that many ignored the warnings.

Based on its internal barometric pressure, Michael was the third most powerful hurricane to hit the US mainland, behind the unnamed Labor Day storm of 1935 and Camille in 1969.

Based on wind speed, it was the fourth-strongest, behind the Labor Day storm, Camille and Andrew in 1992.

Tropical Weather
Kaylee O’Brian weeps inside her home after several trees fell on it during Hurricane Michael (Gerald Herbert/AP)

After Michael left the Panhandle late on Wednesday, Kaylee O’Brien was crying as she sorted through the remains of the apartment she shared with three roommates at Whispering Pines apartments.

Four pine trees had crashed through the roof of her apartment, nearly hitting two people, and her one-year-old Siamese cat, Molly, was missing.

“We haven’t seen her since the tree hit the den. She’s my baby,” Ms O’Brien said.