Charcoal grills can emit deadly carbon monoxide fumes.
The couple was camping with friends. After grilling hamburgers on a tabletop grill, they placed the lid on the grill to extinguish the coals. They visited with their friends until about 10 p.m., then placed the grill in a storage area underneath their camper, watched the news and went to bed. The coals re-kindled and the carbon monoxide from the grill penetrated the floor of the camper, killing the couple. An investigation by Iowa State University found that carbon monoxide from the grill entered the camper in less than two minutes and reached a deadly concentration of 500 parts per million in less than 60 minutes.