3 US Marines died of carbon monoxide poisoning in a car. Vehicle experts explain how that can happen

The deaths of three U.S. Marines who suffered carbon monoxide poisoning in a parked car at a North Carolina gas station have raised questions about how the situation could happen outdoors. Deputies from the Pender County Sheriff’s Office had found the men unresponsive in a sedan in Hampstead. A sheriff’s office spokesman said it seems accidental. Most carbon monoxide deaths occur inside a closed garage or in the home. But automotive experts say certain vehicle malfunctions can cause casualties outdoors. However, they say passengers would smell chemicals or hear the engine making loud noises if there was a dangerous leak.