The cause of death of two young children who were sleeping in their family's van was revealed to be carbon monoxide poisoning and not exposure to the cold as Detroit authorities first thought.

DETROIT, MI – The Wayne County Medical Examiner’s Office determined the two children found not breathing in a minivan outside Detroit’s Greektown Casino died of carbon monoxide poisoning, Fox 2 Detroit reports. Police originally thought the two children, Darnell Currie Jr., 9, and A’millah Currie, 2, froze to death on Feb. 10.

Carbon monoxide is an odorless, colorless gas that takes hundreds of lives each year, and makes even more people sick.

I don’t understand how you could have carbon monoxide when you’re in a car outside, so that’s kind of a puzzle to me.”

Two teenagers were found dead from suspected carbon monoxide poisoning inside a car in the north suburbs early Sunday morning, officials said.

The teens were identified as 17-year-old Yeferson A. Flores Ramos of Hoffman Estates and Litzy Flores, 16, of Carpentersville, the Cook County medical examiner’s office said. Their deaths were ruled accidental as a result of carbon monoxide poisoning from the car exhaust.

Yeferson A. Flores Ramos, 17, of Hoffman Estates, and Litzy Flores, 16, of Carpentersville, were found unconscious in a car early Sunday and pronounced dead from accidental carbon monoxide poisoning.