Lewisville, TX – Lewisville police believe two young adults died from carbon monoxide poisoning after their bodies were discovered Monday morning.

According to police, the bodies of Alejandro Diego Rojas Briceno, 21, and Alejandra Luisangelys Pimental Velazquez, 20, were found in the garage of the Crest Manor Apartments in the 900 block of W. Round Grove Road. Police said Briceno’s stepfather discovered the bodies.

Matt Martucci, spokesman for the Lewisville Police Department, said the car, a Ford Mustang, was running with the air conditioner on, and the garage door was closed when the bodies were discovered.

Martucci said the investigation is ongoing, but he said police do not believe the death was a result of a homicide or a suicide.

“What we do know (is) that there were no signs of trauma to either body, and there was no suicide note found,” Martucci said. “Therefore, this is being treated as an accidental death.”