Alaska State Troopers say an 18-year-old Fairbanks man is in critical condition after shooting himself in the head.
   
Spokeswoman Megan Peters says 18-year-old Nathan Fields is being treated at Alaska Native Medical Center in Anchorage.
   
Troopers say the shooting occurred Thursday at a business and have yet to say whether it was an accident or intentional.
   
Peters declined to release more details, saying the investigation is not over.