Two people, including a child, were killed by falling debris, the U.S. media reported on Thursday.
The storm made landfall near Panama City in the Florida Panhandle on Wednesday, the most powerful hurricane to hit the region since the mid-1800s, according to the Federal Emergency Management Service.
After slamming Florida and lashing Georgia, Michael is far from finished as it swirls northeast, threatening the storm-weary Carolinas.
"Ken Graham, director of the Miami-based National Hurricane Center, said Michael was "unfortunately, a historical and incredibly unsafe and life-threatening situation".
The storm has killed at least 11 people, mostly from trees falling onto houses. Residents emerged in the early evening to assess damage when rains stopped, though skies were still overcast and windy.
Nearby Panama City Beach experienced similar damage along with other communities along the shore of the Gulf of Mexico. Outside, she said in a phone interview, she could see remnants of people's lives strewn about: refrigerators, a beanbag chair, a washing machine, a kayak, and a dresser. I can't think of anything that is more related to hell than that, ' he said.
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.
- Storm riders: Roughly 375,000 people in Florida warned to evacuate; many refused, including 285 people in Mexico Beach where Michael made landfall. Michael's storm surge pushed lead-gray water up to the rooftops. "We still haven't gotten into some of the hardest-hit areas". The Alabama governor also requested a declaration of emergency. On Thursday, Michael was drenching the Carolinas with heavy rains as it headed toward the Atlantic Ocean as a tropical storm.
"We are catching some hell", Timothy Thomas, who rode out the storm with his wife in their home in Panama City Beach, Florida, told the Associated Press news agency.
The hurricane caused windows of buildings to break and roofs to cave in, and submerged homes in floodwaters before heading towards Georgia, The Guardian reported.
"All of America sends its unwavering love and support", he said at the rally. "If we're going to rebuild, do it right". "The roads need to be clear so they can respond as needed without interference".
ABC News' Rob Marciano encountered stray kittens stranded in the storm zone following Hurricane Michael in Panama City, Florida.
But as the cyclone approached and met the Gulf of Mexico, it grew more harrowing.
The Hurricane Center says threats to land are diminishing. On Tuesday morning, wind speeds reached 110, and at nightfall, forecasters believed they would go no higher than 129.
Its rapid intensification caught many by surprise, although the storm later weakened.
Buckingham Research analysts noted that expectations based on hurricane Michael's forecast path before landfall was that the storm's impacts were not likely to be enough to avert pricing pressure discussion at the Baden-Baden Reinsurance Meetings in just over one weeks time.
With a low barometric pressure recorded at 919 millibars, the measure of a hurricane's force, Michael ranked as the third strongest storm on record to hit the continental United States, behind only Hurricane Camille on the Mississippi Gulf Coast in 1969 and the Labor Day hurricane of 1935 in the Florida Keys.