– Bay Medical Center, a 300-bed hospital in the center of town, was a tumultuous mess. Staff members were frantically working on Thursday to evacuate patients just as new ones showed up at the door.

Hurricane Michael had strafed the place, blowing out windows and stripping some of the buildings in the sprawling complex down to their metal girders. Signage was strewn in the streets. Doctors, nurses and workers wandered outside, some crying, some looking for cell service.

The governor had announced that all of the patients in the hospital were to be evacuated. But by midmorning Thursday, at least 100 patients remained inside. And other residents of the ravaged city were still showing up asking for medical care only to be turned away. Wain Hall, 23, was standing with his bicycle, screaming at a security guard by the boarded-up entrance to the emergency room.

“I got a busted head, and so you refuse me medical attention here?” he said.

He lifted his ball cap to reveal matted, blood-soaked hair. “I have lost everything and everyone keeps turning us away,” he said.

As Michael bore down and then passed, some hospitals in the region closed entirely, and others evacuated their patients but kept staff in place to run overwhelmed emergency rooms. In Florida, four hospitals and 11 nursing facilities were closed, according to the Federal Emergency Management Agency.

Gov. Nathan Deal of Georgia said 35 hospitals or nursing homes in the state were without electricity and operating with generators.

Federal health officials said they were moving approximately 400 medical and public health responders into affected areas, including six disaster teams that can set up medical operations outdoors. Some were heading to an overwhelmed emergency department in Tallahassee. Other federal medical personnel were being assigned to search-and-rescue teams to triage people who were rescued.

When a storm like Michael rapidly intensifies, leaving little advance warning, it can be difficult to organize enough specialized medical transportation and patient beds to evacuate people in time, disaster experts said. Previous natural disasters, notoriously Hurricane Katrina, have left hospital and nursing home patients among the most vulnerable. In the wake of Hurricane Irma last year, a dozen residents died at a Hollywood, Fla., nursing home when temperatures spiked and the facility lost air conditioning.

When Hurricane Maria struck Puerto Rico last year, generators failed at hospitals and nursing homes during prolonged power failures, and deaths from chronic illnesses across the population climbed. Patients having medical emergencies at home are also vulnerable. Medical personnel failed to reach some patients in time after Hurricane Harvey flooded the Houston area in August last year.

Bay Medical on Thursday was running with partial electricity from its generators. But there was no water and the toilets were filling up. Windows were broken. One worker said that the fourth floor was flooded — perhaps from leaky windows or roof damage.

Dr. Brian Roake, head of the anesthesiology department, was among those who rode out the hurricane in the hospital. “It was like hell,” he said.