The Greene County medical examiner confirms two found dead in a car in a Walmart parking lot died from carbon monoxide poisoning.

Police found Austin Holt, 21, and Bethany Weems, 26, of Springfield, Mo. dead inside the car at the Walmart Supercenter at Campbell and Walnut Lawn. Both worked at the Walmart.

Medical Examiner Tom Van De Berg says the two likely were taking a break inside the car and fell asleep from the buildup of the poisoning. Investigators say the two were likely inside the car for hours.