Witnesses who spoke with TWRA officers say they found a 56-year-old woman, a 57-year-old man and their dog unconscious in the cabin of a boat. The incident happened around 4:45 p.m. on Norris Lake in Union County.
Those witnesses performed CPR, and all three regained consciousness. The man and the woman were both airlifted to UT Medical Center where they are being treated for high levels of carbon monoxide poisoning.
TWRA officers are investigating the source of the leak.