McFarland, WI- WBAY-TV -A Middleton contractor is dead and three people injured from carbon monoxide build-up after the contractor spent an evening using a gas-powered paint sprayer in an unventilated basement.

Authorities say 26-year-old Cory Nonn was found dead in the basement of the McFarland home in which he was installing drywall. Officials say the carbon monoxide level in his blood was almost 50 percent higher than the level considered life-threatening.

Three residents of the home were pulled from the house and taken to local hospitals where they remain in critical condition. They are 56-year-old Karen Trow, her 18-year-old son Weston Gill, and 57-year-old Eric Thompson.

Carbon monoxide is a colorless, odorless gas that can be fatal in high doses.