Otto Township, MI – Muskegon Chronicle – Police are investigating the deaths of a two suburban Detroit residents who apparently died in their sleep from carbon monoxide poisoning Saturday.

Andrew Joseph Lucas, 24, and Kristina Nicole Francis, 19, both of Warren, were found dead in a trailer in Oceana County’s Otto Township. According to the Michigan State Police Hart Post, the two were visiting friends in the area for the holiday weekend.

The trailer they were staying in did not have a heating source, so they used a portable propane heater they recently purchased. According to the department, the heater was designed for outside use only and should not have been used as a home heating source.

The couple apparently was overcome by fumes from the heater due to a lack of ventilation. The incident remained under investigation this morning, but authorities were focusing on possible carbon monoxide poisoning.

In a similar incident in 2003, two anglers on a church outing died after being overcome by carbon monoxide fumes from a propane heater as they took a break inside a van, authorities said.

David B. Arnold, 23, of Bronson, and 14-year-old Cory D. McCurley, of Coldwater, were found unconscious around 3 a.m. Sunday. Efforts to resuscitate them failed, and they were pronounced dead at West Shore Medical Center in Manistee.

A third person, 17-year-old Jeremiah G. Teller, of Bronson, was revived.

The three were on a fishing trip near Tippy Dam, a popular fishing spot 3 miles east of Brethren, and took a propane heater to their van.