After almost 3 hours of strong winds and heavy rains, Michael flooded homes and streets, and toppled trees and power lines in the Gulf of Mexico beachfront area.
A state emergency-management official said all hospitals in the impacted region have reported some form of "critical failure" - water and sewage problems or infrastructure issues such as crumbling walls - that required patients to be relocated and medical field hospitals to be set up.
Meanwhile, thousands of National Guard troops, law enforcement officers and rescue teams still had much to do in the hardest hit area: Florida's Panhandle. "This is obviously the worst", said Stephanie Palmer, a FEMA firefighter and rescuer from Coral Springs, Fla.
The storm made landfall near Mexico Beach, with wind speeds reaching 155 miles per hour (249 kph) - just shy of a Category 5 hurricane.
Though the storm has now weakened, it is continuing on a unsafe path across the southeast states.
The 17 victims comprised eight from Florida, five in Virginia, three in North Carolina, and a child in Georgia. Authorities also are searching for a missing woman whose vehicle was swept away by floodwaters.
Nearly 1.1m homes and businesses were without power from Florida to Virginia early on Friday, according to utility companies.
FEMA's Long urged communities such as Mexico Beach, where many homes were obliterated by 12 to 3.7 to 4.3 metres of storm surge, to rebuild to withstand future storms. "We have to wait for our assessment to be completed before we can say how many are missing", said Uganda Red Cross spokeswoman Irene Nakasiita.
"We were going to establish a mortuary location".
England on the road to being an worldwide force - Southgate
The most important thing for the team is we create chances, look unsafe , and the players who didn't score tonight will score'. Croatia and England will face off in a UEFA Nations League group stage contest on Thursday, Oct. 12.
May struggles to sell at home Brexit deal emerging with EU
Cabinet ministers raised concerns about potential compromises with the European Union over Brexit at a No 10 meeting on Thursday. A negotiated Brexit, and Theresa May's survival, hinge on whether her ministers and MPs can live with this paradox.
Mohamed Salah injured in Egypt win
SABC said it was willing to pay $600,000 a year. "What I would be more anxious about is if he wasn't getting chances". Guinea leads the group after beating Rwanda 2-0.
The storm, which came ashore as a category 4 on the five-step Saffir-Simpson hurricane scale, tore entire neighborhoods apart, reducing homes and businesses to piles of wood and siding, damaging roads and leaving scenes of devastation that resembled the aftermath of a carpet-bombing operation.
Aerial footage shows the extent of the damage from Hurricane Michael in Mexico Beach.
People look on at a damaged store after Hurricane Michael passed through on October 10, 2018 in Panama City, Florida.
The number of fatalities was expected to rise further as no deaths have been reported from oceanfront communities, such as Mexico Beach, Port St. Joe and Panama City, that bore the brunt of the storm's wrath.
Patterson estimated 1,000 homes were completely or partially destroyed in his town of 3,500.
She said local television stations were knocked off the air for two days, and authorities were relying on the Gulf State College radio station to broadcast public service bulletins.
"What's happening is search and rescue is trying to get into the rubble to make sure that there's nobody covered up, trying to assess if there's additional casualties there", Long added.
An insurance company that produces models for catastrophes estimated Michael caused about $8 billion in damage, the Associated Press reported.