KOSCIUSKO COUNTY, Ind. (WANE) – State police are investigating the deaths of three teenagers who were found in a car Sunday afternoon in Kosciusko County.

According to a release from Indiana State Police, troopers responded to a call reporting the teens had been found unresponsive in a car just after 3 p.m.

On a property off West 900 North near Etna Green, troopers said they found a blue 2008 Ford with an unresponsive male in the driver’s seat, identified as 18-year-old Robert Bontrager from Rome City. According to the release, troopers also found two 16-year-olds in the back seat, identified as Karen Miller and Nathan Yoder, both from Topeka in LaGrange County.

All three were pronounced dead at the scene, according to ISP.

Sergeant Ted Bonner with ISP confirmed to WANE 15 the car was not parked inside the property. He said the police suspect there was an issue with the car’s exhaust system. 

The release said autopsies performed Monday in Fort Wayne point to carbon monoxide poisoning as the cause of death, but toxicology results are pending.

While Bonner said there was speculation within the community that the deaths were drug-related, he said he feels the coroner’s report rules that out. Bonner also said he doesn’t think it was a suicide.

Bonner said the incident is still under investigation by ISP.