A Florida nursing home under investigation for the deaths of 13 patients after Hurricane Irma says in a letter to Congress that staff members did everything possible but couldn't overcome a lack of power to the central air conditioner.

In a letter released Monday, Rehabilitation Center at Hollywood Hills attorney Geoffrey D. Smith told the House Energy and Commerce Committee that employees followed proper procedures between the air conditioner losing power on Sept. 10 and when the deaths began Sept. 13. The committee is investigating the deaths as are local police detectives and the state.

Smith said managers made repeated calls to Florida Power & Light, the state health care administration and Gov. Rick Scott in an effort to get the air conditioning power restored but got nowhere. Meanwhile, he says the facility's main power never went out and employees used portable air conditioners and fans to cool the patients and kept them hydrated. There was no state law requiring nursing homes to have backup generators for their central air conditioners.

He said staff had been closely monitoring patients for two days when the deaths began without warning. He said the temperature inside the facility never exceeded 81 degrees, which would be within standards.

“We believe that there were multiple system failures that need to be considered and investigated before casting blame on persons who risked their own well-being to care for others during this natural disaster,” Smith wrote.

Scott's office issued a statement Monday saying, “This facility had a responsibility to its patients to protect life during emergencies. We must learn why this facility chose not to evacuate their patients to the hospital across the street or call 911.”

Florida Power & Light says it followed the priority list for restoration as agreed to by Broward County.

Smith wrote in his letter that from Sept. 10 to 12, the staff monitored the facility's 150 patients and none exhibited any sign of heat exhaustion.

He said about 3 a.m. on Sept. 13, several patients began showing signs of respiratory and cardiac distress. He said the staff summoned paramedics for each patient and followed proper protocols.

“The onset of heat stroke is impossible to predict and can occur in 10 to 15 minutes,” he said. He said the elderly are susceptible at 81 degrees.

He said about 6 a.m., Hollywood police officers and staff from Memorial Regional Hospital, the trauma center across the street, declared a mass casualty situation. Officers and hospital staff members have said the facility seemed excessively hot. Detectives took a temperature reading but that has not been released.

All patients were evacuated to Memorial over the next three hours. Three patients died at the nursing home, five later that day at Memorial and five in subsequent days at the hospital. A 14th death was later determined not to be related. The dead ranged in age from 57 to 99, with most from their 70s to 90s.

Smith rejected criticism that the center should have evacuated its patients to Memorial earlier, saying that would violate established emergency procedures.

“Hospitals are critical facilities that are supposed to be used for individual cases,” not as mass evacuation centers, he wrote.

Shortly after the evacuation, an FPL crew arrived and restored the air conditioning's power in 20 minutes, he wrote.

He said 242 other Florida nursing homes lost power. He said he is seeking information on deaths at other facilities to see if they spiked during the blackout.

Terry Spencer reports for the Associated Press.