KNXV-TV(GLENDALE, Ariz.) — An 18-month-old girl died after she was left in her family’s car for several hours, Arizona authorities said.

The child’s death is being investigated as a possible hot car case, said police in Glendale, where the temperature reached 88 degrees Monday.

When the baby’s father found the girl inside the car at an apartment complex Monday afternoon, officers were sent to the scene.

The baby had been there for at least a few hours and “died from being left inside the vehicle,” police said in a statement, adding that the parents were at the scene and spoke with detectives.

“Both parents are cooperating with detectives and they are very upset over losing their child,” Glendale police spokeswoman Tiffany Ngalula told ABC News via email Tuesday.

“We will not be releasing their names as we are still working with them through this tragedy to determine exactly what occurred,” she continued. “We have not formally submitted any charges at this time as we still have key portions of the investigation to complete.”

The little girl’s autopsy is scheduled for Tuesday, Ngalula said.

As the investigation continues, the police department urged, “Always check twice for loved ones left inside of a vehicle that do not have the ability to get out on their own, because we are ultimately responsible for them.”

While it was not immediately clear if the baby’s death was hot car related, public safety group KidsAndCars.org warns that last year was the worst in history for child hot car deaths in the U.S., with a total of 52 fatalities.

“Hot car deaths continue to take place because nobody believes this could happen to them,” KidsAndCars.org spokesperson Amber Rollins said in a statement Tuesday.

If the Arizona case is confirmed to be hot car related, it will mark the third hot car death of the year, according to KidsAndCars.org.

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