North Harris County, TX – Three people are dead after high levels of carbon monoxide were reported Wednesday night in north Harris County.

It happened at a home in the 8500 block of Scotch Pine Place after a neighbor went to the house and spotted someone lying on the ground.

In all, three people were found dead inside different parts of the home. A fourth man was found still alive when first responders arrived at the scene. That person was rushed to a hospital in stable condition.

Officials with the Harris County Sheriff’s Office says preliminary information suggests it may be carbon monoxide poisoning. They say CO levels were 7 times higher than normal. Firefighters used a chainsaw to ventilate the home so they can go in for investigation.

The Klein Fire Department and Harris County Fire Marshal’s Office will handle the investigation.