MANKATO, Minn. (AP) - Authorities in southern Minnesota say the investigation continues into the death of a 16-year-old girl whose body was found in a field.

The Blue Earth County Sheriff's Office says an autopsy has been completed on Hannah Kathleen Oliva of New Ulm, but her official cause and manner of death won't be available until lab test results are back.

Authorities say they got a call around 6:30 a.m. Wednesday about a car sitting in a field off of Highway 68 northwest of Mankato. A deputy found the unoccupied vehicle stuck in the mud and later found the unresponsive girl lying face down in the field. She was dead at the scene.

Oliva was a junior at Mankato West High School.