The Lewis & Clark County Coroner says carbon monoxide poisoning appears to be the cause of death for 28-year old Kevin Fauntleroy.
Fauntleroy, along with five other people, was taken to St. Peter's Hospital in Helena on Saturday for reports of possible carbon monoxide poisoning.
Just before 8:30 p.m, emergency responders arrived at the home on the 1800 block of 8th Avenue for reports of people feeling ill from possible poisoning.
The six people in the residence were then taken to the hospital for treatment.
An autopsy will be conducted to confirm Fauntleroy's cause of death.
The other five victims are expected to make a full recovery.
Vince Williams of the Helena Fire Department said the acceptable level of carbon monoxide in the air is 35 parts per million, and there were sections in the house where the carbon monoxide levels were 1,700 per million.
Williams noted, "The easy answer is carbon monoxide detectors; there were no carbon monoxide detectors in this residence. If you have a gas or any type of gas appliance in your house you need to have a gas detector."
The incident is still being investigated.
Information from the U.S. Centers For Disease Control & Prevention:
What are the symptoms of CO poisoning?
The most common symptoms of CO poisoning are headache, dizziness, weakness, upset stomach, vomiting, chest pain, and confusion. CO symptoms are often described as “flu-like.” If you breathe in a lot of CO it can make you pass out or kill you. People who are sleeping or drunk can die from CO poisoning before they have symptoms.
How can I prevent CO poisoning in my home?