A preliminary investigation indicated carbon monoxide was a factor, and the cause of the release of the gas is under investigation, State Police said. Autopsies have been scheduled for Monday to verify the victims' cause of death.
Anyone with information that could assist the investigation can contact the State Fire Marshal's Office at 603-223-4289 or fmo@dos.nh.gov.
State Fire Marshal Sean P. Toomey said residents should ensure they have working carbon monoxide alarms in their homes by testing them monthly.
Alarm batteries should be changed during daylight saving time each year and any time an alarm starts chirping, which is an indicator of a low battery, the statement said.
Carbon monoxide is a colorless, odorless, tasteless gas that is known as the "silent killer." Signs and symptoms of carbon monoxide poisoning may include headache, weakness, dizziness, nausea, or vomiting, as well as shortness of breath, confusion, blurred vision, or loss of consciousness, the statement said.