The death of a 4-year-old Pennsylvania girl who was left in a car for hours on a hot day apparently was an accident, although negligence may have been involved.

Lycoming County coroner Charles Kiessling Jr. said an autopsy didn't provide a definitive cause for Samaria Motyka's death Friday.

Williamsport police expect toxicology tests to take several weeks.

A woman who was supposed to take the child to a day care center instead drove to downtown Williamsport then went to work, leaving the girl unattended in the vehicle for several hours, police agent Raymond Kontz III said. Temperatures would have been in the high 90s at the time, according to the National Weather Service.

"We don't know how the woman could have left the girl in the back of the car," Koontz said. "That is still under investigation."

Assistant Chief Timothy Miller said that while negligence may have been involved, it appears the death was a tragic accident. He said the woman was in a relationship with the girl's father and regularly cared for her.

The woman was remorseful and cooperating with investigators, including taking a blood test for drug or alcohol consumption, Miller said.