WATCH: 'Unfathomable' -- 8 dead at Florida nursing home after Irma

Hurricane-scarred Florida warily eyed the fate of its most vulnerable residents and emergency workers were urged to immediately check on those in nursing homes after eight people died in a scorching facility that lost its air conditioning in the storm.

Even in the face of a storm that shrouded nearly the entire state and had officials still piecing together its destruction, the news Wednesday from the Rehabilitation Center at Hollywood Hills stood out, with victims as old as 99 among the dead and worries the count could grow.

"Unfathomable,” Gov. Rick Scott said. “Inexcusable,” Sen. Bill Nelson added.

Elsewhere in South Florida, other alarms were sounded for older residents. In Coral Gables, an apartment building was evacuated after authorities said its lack of power made it unsafe for elderly tenants. And at the huge, 15,000-resident Century Village retirement community in Pembroke Pines, where there were also widespread outages, rescue workers went door to door in the 94-degree heat checking on residents and bringing ice, water and meals.

Though the number of people with electricity had drastically improved from earlier in the week, some 6.8 million people across the peninsula continued to wait for power, and utility officials warned it could take a week or more for all areas to be back up and running.

As the state continued to piece itself back together, President Donald Trump was due to visit Naples in southwestern Florida on Thursday.

Not counting the nursing home deaths, at least 17 people in Florida have died under Irma-related circumstances, and six more in South Carolina and Georgia, many of them well after the storm had passed. The death toll across the Caribbean stood at 38.

In Hollywood, the Rehabilitation Center said the hurricane had knocked out a transformer that powered the air conditioning. Broward County said the home alerted officials Tuesday that it had lost power, but when asked if it had any medical needs or emergencies, it did not request help.

Early Wednesday morning, after responding to three calls about patients there in distress, firefighters went through the facility and found three people dead and evacuated more than 150 patients to hospitals, many on stretchers or in wheelchairs, authorities said.

By the afternoon, five more had died. Others were treated for dehydration, breathing difficulties and other heat-related problems.

It’s a sad state of affairs,” said Hollywood Police Chief Tom Sanchez, who said investigators believe the deaths at the Rehabilitation Center were heat-related and said the building has been sealed off and a criminal investigation underway. The chief said authorities have not ruled anything out in the deaths, including carbon monoxide poisoning from generators. He also said investigators will look into how many windows were open.

Across the street from the stifling nursing home sat a fully air-conditioned hospital, Memorial Regional.

Glendale Owens, the daughter of one of the men who died, said she last visited her father in the nursing home Monday and everything seemed fine. She said Bobby Owens had been at the facility for more than 10 years.

“People are telling me different things,” she said Wednesday evening. “But nobody from the facility has told me anything yet.”

Paulburn Bogle, a member of the housekeeping staff, said after the air conditioning failed, the staff used fans, put cold towels and ice on patients and gave them cold drinks. The medical examiner’s office said the victims were five women and three men, ages 70 to 99.

Scott vowed to punish anyone found culpable in the deaths. Nelson demanded a federal investigation.

Calls to the owner and other officials at the Hollywood home were not immediately returned, but the facility’s administrator, Jorge Carballo, said in a statement that it was “cooperating fully with relevant authorities to investigate the circumstances that led to this unfortunate and tragic outcome.”

The governor announced in a news release Wednesday night that he’s directed the Agency for Health Care Administration to issue an emergency moratorium for the facility, preventing it from admitting new patients indefinitely.

Nursing homes in Florida are required by law to file an emergency plan that includes evacuation plans for residents. County officials released documents showing that the Hollywood facility was in compliance with that regulation and that it held a hurricane drill with its staff in October.

Around the state, hazards were popping up in the aftermath of the storm. At least six people in Florida died of apparent carbon monoxide poisoning from generators, and a Tampa man died after the chain saw he was using to remove trees recoiled and cut his carotid artery.

The number of people in shelters across the state fell to less than 13,000.