Eight residents of a Florida nursing home have been reported dead of heat-related causes after their facility was left without electricity or air conditioning in the wake of Hurricane Irma, authorities said on Wednesday.

Local police opened a criminal investigation into the incident Wednesday after they were called to The Rehabilitation Center at Hollywood Hills, FL, in response to a resident having a heart attack. There they found “several patients in varying degrees of medical distress,” officials said in a report.

Three patients were dead inside the facility; as of press time five others had died after being evacuated. Police and firefighters evacuated 115 residents from the facility.

Employees of the facility told reporters their power had been knocked out during Hurricane Irma, and that they were using a generator to cook meals but not for air conditioning. Workers reportedly tried to keep residents cool with cold drinks, fans, ice and cold towels as temperatures reached into the 80s.

The son of one resident told the Miami Herald that portable air conditioning units were in use when another relative visited the facility earlier this week, and that it was “a little warm, but not uncomfortable.” Other relatives told the media the facility “felt like 115 [degrees] inside.”

In a statement to local media, Jorge Carballo, administrator at The Rehabilitation Center, said “several patients experienced distress and there were [three] fatalities” in the building following the power outage, which affected the transformer that powers the facility’s air conditioning system.

“Facility administration has been in communication with Florida Power & Light and the Governor’s office since the beginning of Hurricane Irma, and is cooperating fully with relevant authorities to investigate the circumstances that led to this unfortunate and tragic outcome,” Carballo wrote.

On Twitter Florida Governor Rick Scott (R) said he is planning to “aggressively demand answers” on how the “unfathomable” incident happened, and will hold anyone who “wasn’t acting in the best interests of their patients” to the “fullest extent of the law.”

Authorities were also instructed to carry out precautionary checks on other long-term care facilities in the area in the wake of the incident.