Emergency officials said they had done an initial "hasty search" of 80 percent of the stricken area, looking for the living or the dead. Senior said as of Friday morning that there were "more staff than patients" still at the hospital.
Sally Crown rode out Michael on the Florida Panhandle thinking at first that the worst damage was the many trees downed in her yard.
Florida Senator Marco Rubio said restoring power was going to be "long & difficult" as the storm "shredded" its electric grid.
Sheriff Smith said the 12,000 residents of Franklin County received evacuation warnings from multiple sources, including Mr. Scott.
Which areas are worst affected?
Michael crashed ashore near Mexico Beach on Wednesday afternoon as one of the most powerful storms in US history, with winds of up to 155 miles per hour (250 kph).
The storm, which in less than two days grew from a tropical storm to a Category 4 hurricane on the five-step Saffir-Simpson scale, tore apart entire neighbourhoods in the Panhandle, reducing homes to naked concrete foundations or piles of wood and siding.
"I think you're going to see it climb", Brock Long, administrator of the Federal Emergency Management Agency, said of the death count at a news conference.
Apalachicola, with 2,300 residents, was also badly affected, the mayor reporting that downed cables were making it hard to get through the town.
On Saturday, emergency crews will continue descending into the coastal cities in the Panhandle, like Mexico Beach, that were wiped out and will try to reach remote areas that were isolated by downed trees and power poles. "The people of Florida rely on Governor Scott for accurate storm response and safety information - and a false ad suggesting Floridians should not listen to the Governor isn't just ill-timed, it's unsafe".
"We lost our dock". That home is now smashed, with no sign of the woman. This was her dream retirement place she tells me - the last four years spent doing it up. "I was picking three bale cotton (this week); today it is gone", cotton farmer and state Rep. Clay Pirkle said.
"You can't make sense of it, but what you do is you take the situation, and what we have to make certain that our kids know is that we must be resilient", Smith said. Those numbers are added to almost 345,000 accounts without power in Florida and 150,000 in Georgia.
Florida officials say one man died when he was crushed in an incident involving a tree in Gadsden County.
The scenes were familiar across communities in Florida and Georgia: uprooted trees cracked like toothpicks, buildings with roofs peeled off, homes flattened into an unrecognizable landscape.
"It's total devastation - no power, no water, no communication", she said.
Michael earlier reportedly killed at least 13 people as it passed through Central America: six in Honduras, four in Nicaragua and three in El Salvador.
Nearly 1.2 million homes and businesses were without power from Florida to Virginia on Thursday because of the storm.
Around 6,000 are thought to have sought refuge in official shelters, mainly in Florida.
As Michael plows northward up the Atlantic seaboard, the governors of North and SC urged residents to brace for more heavy rain and storm-force winds.
The NHC warned that communities in north-west Florida and North Carolina faced the threat of life-threatening flooding as rising water moved inland from the coast.
In North Carolina, still struggling to recover after Florence, up to 152mm of rain had fallen in the mountains by morning, and people had to be rescued from cars trapped in high water.