Hollywood Police Chief Tomas Sanchez said that the authorities were investigating the deaths and looking at every possibility, adding that nothing would be ruled out, including a criminal angle to the investigation.
A statement from the nursing home, the Rehabilitation Center at Hollywood Hills, confirmed that it had a "prolonged power failure to the transformer which powered the facility's air conditioning system as a result of the hurricane".
Hollywood authorities say an issue with an air-conditioning unit at The Rehabilitation Center nursing home has led to the evacuation of 115 people and the deaths of at least six residents.
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.
Florida Power & Light provided electricity to parts of the nursing home but the facility was not on a county top-tier list for emergency power restoration, the utility said.
"Evacuating 133 people is quite an undertaking", said a police department spokesperson.
The building has been without power since Hurricane Irma struck.
The utility said in a statement Wednesday that it was limited in what it could reveal because of the investigations.
Shocked Americans were struggling on Thursday to understand how eight elderly people in a Florida retirement home - directly across the street from a hospital - could have died in the days following Hurricane Irma's devastating passage.
Aside from the nursing home deaths, at least 13 people in Florida were killed in Irma-related circumstances, many of them well after the storm had passed. Although the details of these reported deaths are still under investigation, this situation is unfathomable. "That's why we are camped out there and doing whatever we can to assist them in this process".
Moulder wasn't the only person with family at the facility who found out about the tragedy while watching the news. The staff used fans, put cold towels and ice on patients and gave them cold drinks, he said. Local governments had begun evacuating elders from other long-term care facilities across South Florida that have lost power in the wake of Hurricane Irma.
It says it's focusing first on restoring power at schools, hospitals and other critical infrastructure.
Of Florida's total 309 hospitals, all operational facilities have power or are running on generator power.
As of Tuesday evening, 114 of Florida's nursing homes were relying on generators for power.
The incident prompted police to check on the 42 other nursing homes in Hollywood, which is located on Florida's Atlantic coast less than 20 miles north of Miami.
"Approximately 150 facilities out of the almost 700 (nursing) facilities in the state do not now have full power services restored", the statement said.
Hollywood police later tweeted that they had evacuated 158 patients to local hospitals.
In addition to severe flooding across Florida and extensive property damage in the Keys, one of the chief hardships facing Floridians has been widespread power outages that initially plunged more than half the state into darkness. "It should be- we know this is coming and it's a week away and you need to be moving these people out", he said.