While making a routine check of a parking garage Sunday morning, a police officer discovered two dead individuals inside a running car.

Tuesday email from New Haven Police Department spokesman David Hartman revealed that NHPD Officer Arpad Tolnay was inspecting the first level of the parking garage when he noticed that a black Volkswagen Jetta’s engine was still running, even though it was parked. Opening the door released the smell of exhaust and revealed the two bodies, one in the front seat and one in the back.

Tolnay called EMTs immediately, but neither person could be revived. After bringing in a death investigator from the Medical Chief Examiner’s office to investigate the scene, police revealed that the deaths were likely accidental and caused by carbon monoxide poisoning. The investigation did not reveal signs of trauma to either person.

Police identified the person in the front seat was identified as Monroe, Conn., resident Michael Longo and the second person as New Fairfield resident Amy Nickerson.

Detectives at the scene also discovered that the car had a blown out tire and damage to the exhaust system.

The parking garage is located on 200 Orchard Street.