The Arkansas State Police is investigating the death of a 3-year-old girl and injury to her 15-month-old sister.
"Both are the apparent victims of heat while they were inside a car parked outside their mother's home in Booneville [on Monday]," according to a news release from the state police.
Kaylee Petchenik, 21, of Booneville called police about 2 p.m. Monday saying she awoke from a nap to find her children missing.
A Booneville police officer who responded to the call found the children, both unconscious, lying on the back floorboard of the car, according to the state police.
Laykn Petchenik was later pronounced dead at a Booneville hospital. Her body has been transported to the state Crime Laboratory for autopsy.
Olivia Petchenik was in stable, but critical condition Tuesday at a Little Rock hospital, according to the state police.
Special agents with the state police Criminal Investigation Division are leading the investigation and will submit a case file to the Logan County prosecuting attorney for consideration, according to the release.
Robert Darby, a meteorologist with the National Weather Service in Tulsa, said it was 95 degrees in the Booneville area at 2 p.m. Monday.
He said the heat index at that time was 101 degrees. Darby described Monday as a "full-sun day" with little cloud cover.