HOFFMAN ESTATES, Ill. Two teenagers who were found unresponsive inside a locked vehicle and subsequently pronounced dead overnight in northwest suburban Hoffman Estates have been identified, according to the Cook County Medical Examiner’s Office (CCMEO).

The two teens were identified by the CCMEO as 17-year-old Yeferson A. Flores Ramos and 16-year-old Litzy Flores.

The Hoffman Estates Police Department said they are now conducting a death investigation, but they say a preliminary autopsy indicates the cause of death appears to be accidental carbon monoxide poisoning.

According to police, officers responded just after 12:30 a.m. to the 200 block of East Berkley Lane, along with the Hoffman Estates Fire Department, for a report of two people inside a locked vehicle who appeared to be unconscious and not breathing.

Upon arrival, police and fire officials located a 17-year-old boy and a 16-year-old girl who were both unresponsive. After emergency personnel forced entry into the vehicle, police say the teenagers were extracted and immediately given life-saving measures.

They were then taken to St. Alexius Medical Center in Hoffman Estates, where they were both pronounced dead. The case remains under investigation, police say.