1-year-old girl dies after she's left alone in car on hot day

A 1-year-old girl died after she was left alone in a car on a hot Iowa day, according to police.

Officers were called to a Sioux City home on a report of an unconscious child just before 4 p.m. Sunday and found a 16-month-old girl in a car, said Sioux City police.

The temperature reached 98 degrees with a heat index of 107 degrees in Sioux City on Sunday.

The girl, who was unresponsive, was taken to Unity Point St. Luke's Hospital where she was pronounced dead, said police.

The 16-month-old's death is being investigated as a possible hot car case "but we are not ruling what the cause of death is until medical reports are finalized," Sioux City police Lt. Chris Groves told ABC News on Monday.

Groves did not say how long the child may have been in the car.

This marks the 16th child to die in a potential hot car case so far this year, according to national nonprofit KidsAndCars.org.

Hot car deaths reached a record last year with at least 52 children killed, according to KidsAndCars.org.

Click here for hot car safety tips.

ABC News' Sam Wnek contributed to this report.