PORT ST. JOE, Fla. (Reuters) - Dazed Florida residents picked through the wreckage left by Hurricane Michael on Thursday after the near-record-force storm tore apart coastal towns and was blamed for seven deaths.

Michael smashed into Florida's northwest coast near the small town of Mexico Beach on Wednesday with screeching 155 mile per hour (250 kilometer per hour) winds, pushing a wall of seawater inland.

"The wind was really tearing us apart. It was so scary you’d poo yourself,” said retiree Tom Garcia, 60, who was trapped inside his Mexico Beach home as water poured in to waist height.

He and his partner Cheri Papineau, 50, pushed on their door for an hour to stop the storm surge bursting in as their four dogs sat on top of a bed floating in their home.

The beach town looked like it had been carpet bombed, with little left in the first blocks from the beach. Further inland, about half the homes were reduced to piles of wood and siding. Helicopters flew overhead looking for survivors as bulldozers plowed paths along roads filled with shredded homes.

Cheryl Shipman, 72, pointed to a few broken red wooden boards, saying "this used to be my three storied house."

Michael, the third most powerful hurricane ever to hit the U.S. mainland, weakened overnight to a tropical storm. But it marched northeast, toppling trees with 50 mph (80 kph) winds and bringing "life threatening" flash flooding to areas of Georgia and Virginia, still recovering from Hurricane Florence.

At least seven people were killed in Florida, Georgia and North Carolina from falling trees and other hurricane-related incidents, according to state officials.

Emergency services carried out dozens of rescues of people caught in swiftly moving floodwaters in North Carolina.

Virginia declared a state of emergency in advance of the storm.

Many of the injured in Florida were taken to hard-hit Panama City, 20 miles (32 km) northwest of Mexico Beach. Gulf Coast Regional Medical Center was treating some, but the hospital evacuated 130 patients as it faced challenges of running on generators after the storm knocked out power, ripped off part of its roof and smashed windows, a spokesman for the hospital's owner HCA Healthcare said in an email.

CHECKING DOOR TO DOOR

Buildings in Panama City were crushed, tall pine trees were sent flying and a steeple was knocked off a church.

At the city's Jinks Middle School, the storm peeled back part of the gym roof and tore off a wall. A year ago the school welcomed students and families displaced by Hurricane Maria in Puerto Rico.

"I have had employees going to the communities where our kids live, going door to door and checking," said Principal Britt Smith by phone. "I have been up since 3:30 or 4 a.m. emailing and checking on staff to see if they are safe. So far, everybody seems to be very safe."

Fast-moving Michael, a Category 4 storm on the five-step Saffir-Simpson hurricane scale when it came ashore, was about 20 miles (35 km) northwest of Raleigh, North Carolina, at 5 pm EDT (1900 GMT) and set to speed up as it headed for the Atlantic coast, the NHC said.

Nearly 950,000 homes and businesses were without power in Florida, Alabama, the Carolinas and Georgia on Thursday.

The number of people in emergency shelters was expected to swell to 20,000 across five states by Friday, said Brad Kieserman of the American Red Cross.

ROOF-HIGH FLOODING

Michael pummeled communities across the Panhandle and turned streets into roof-high waterways.

Much of downtown Port St. Joe, 12 miles (19 km) east of Mexico Beach, was flooded after Michael hit with 155 mph winds, snapping boats in two and hurling a large ship onto the shore, residents said.

"We had houses that were on one side of the street and now they’re on the other,” said Mayor Bo Patterson, who watched trees fly by his window as he rode out the storm in his home seven blocks from the beach. Patterson estimated 1,000 homes were completely or partially destroyed in his town of 3,500.

Brad Rippey, a meteorologist for the U.S. Agriculture Department, said Michael severely damaged cotton, timber, pecans and peanuts, causing estimated liabilities as high as $1.9 billion and affecting up to 3.7 million crop acres (1.5 million hectares).