On Monday, two people died of apparent carbon monoxide poisoning in Bruce Township, according to the Macomb County sheriff's department. The department referred requests for details to state police, who declined comment Tuesday.
About 400 people die nationwide each year from carbon monoxide poisoning, according to the U.S. Centers for Disease Control and Prevention.
Carbon monoxide is created when something burns without an adequate supply of oxygen. It can come from defective furnaces or space heaters used with inadequate ventilation.