According to WOAI-TV, San Antonio police responded to the house about 5 p.m. Saturday, hours after the family of four had returned home from a T-ball game about 1 p.m.
Police believe that the parents became distracted after getting the boy's 6-year-old brother out of the car and accidentally left the toddler inside the vehicle. Meanwhile, outside temperatures climbed into the mid-90s, WOAI reported.
"One parent thought the other parent had grabbed both of the children, and, in fact, only the 6-year-old had been taken out of the car," San Antonio police Lt. Jesse Salame said, according to ABC News. "By the time they realized it several hours had passed, and when they got the child out of the vehicle, he was not responsive."
Paramedics tried but were unable to revive the boy, WOAI reported.
Police called the death "a tragic or horrific accident," according to the TV station.
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