COLLIER COUNTY, Fla. (WFLA) – Two teenagers were found dead in a Florida park on Wednesday evening.

According to the Collier County Sheriff’s Office, a park ranger discovered a vehicle with the engine running around 9 p.m. and notified deputies.

When deputies arrived they found the two teens unresponsive inside the vehicle and smelled a strong odor of exhaust fumes.

The 18-year-old man and 17-year-old girl were pulled from the car. The man was pronounced dead at the scene, and CPR was performed on the girl before she was taken to NCH Downtown Baker, where she was pronounced dead a short time later.

An examination of the vehicle determined that its exhaust system had been modified, according to investigators.

“Autopsies are pending to determine a cause of death but preliminary observations by deputies at the scene indicate that the deaths may have resulted from accidental carbon monoxide poisoning related to a modified exhaust system on the vehicle,” CCSO said.