Commerce City, CO – An investigation was underway at a Commerce City home Tuesday, after police found one man dead and seven other occupants suffering from carbon monoxide poisoning.

Authorities won’t confirm that’s the cause but sources tell FOX31 Denver News everyone inside the home was overcome by carbon monoxide.

The Adam’s County Sheriff’s Office confirmed that deputies were called to the 7800 block of Kenwood Street, which is near Vasquez Boulevard and I-76, around 6 a.m.

When they arrived, deputies found a dead body and worked to transport four adults and three children to Presbyterian/St. Luke’s Medical Center in Denver.

Friends identified the man who died as 55-year-old Calixto Ascensio. “He worked for me for a long time,” says a friend, Juan Blanco. “I’ve known him for a long time. His brother works for me right now.”

The brother lives in the house to help make ends meet along with Ascensio’s wife and several children ranging in age from about 8 to 22.

A man who says he is one of the victim’s cousins arrived late Tuesday afternoon and says he had concerns about the heating unit in the house. “It’s too late,” says Dionicio Ramos. “It’s too late now.”

Neighbors say firefighters told them the family suffered carbon monoxide poisoning. Xcel Energy crews were on scene inspecting gas and electrical lines going into the house.

“He was a very good man, good father,” Juan Blanco says about the man who died.

Energy Outreach offers a number of safety tips for people to consider regarding the danger of carbon monoxide in homes.

– Install a carbon monoxide (CO) detector near bedrooms to detect dangerous build-ups. CO can`t be detected by smell, taste or sight and can reach dangerous levels when fuels such as natural gas, kerosene, wood or gasoline don`t have enough oxygen to burn efficiently.

– Make sure heating vents are not blocked and the furnace is cleaned and maintained.Change furnace filters once every two months and do not store flammable liquids in the same room.

– With a wood-burning fireplace, have the chimney inspected and cleaned annually and use a sturdy fireplace screen.Do not burn trash because it can burn too quickly.

– Check that power and extension cords are certified by an independent testing laboratory and aren`t frayed, cracked or cut.Follow the rating for indoor or outdoor use.

– With candles, use sturdy, safe candleholders that can collect dripping wax.Keep them away from children and anything that can ignite, such as clothing, books, paper, curtains and flammable liquids.Blow them out when you leave the room or go to sleep.

– Make sure portable electric space heaters carry the mark of an independent testing laboratory (US, CSA or ETL) and have an automatic shut-off feature.

– Never use an extension cord with a space heater. Always plug the heater into the wall socket and keep all flammable materials including furniture at least three feet away.

– Keep firefighting materials on-hand. These include dry powder fire extinguishers, a tarp or heavy blanket, sand, salt, baking soda and water.

– Don`t thaw frozen pipes with a blow torch or other open flame.Use warm water or a UL rated hand-held blow dryer.