The Monroe County Sheriff's Office said a 3-year-old boy is dead after he was found inside a locked car.

Authorities said the incident is still under investigation. Deputies responded after the child was found unresponsive in a locked car after being left there for around 35 minutes.

Authorities said they arrived on the scene at 1:15 p.m. Attempts to revive the child were unsuccessful.

The death was a result of the heat, and the investigation is ongoing.

Investigators said they spoke to the child's grandmother and guardian, who said she had been mowing the neighbor's lawn at the time.

The grandmother told authorities the child had been left in the care of a 15-year-old at the residence who was watching other children at the time.

At some point, the grandmother noticed the boy wasn't around and asked the teen where he was, according to deputies.

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