The Warrick County Sheriffs Office is investigating the accidental death of a teenager. Investigators say 17-year-old Karissa Krohn voluntarily inhaled butane last week and lost consciousness. She was then transported to the hospital where she was pronounced dead. The corners office says she died from asphyxiation. Some of Karissas friends told family members that she had inhaled the substance one other time and it had no affect on her. Karissa was a senior at Boonville High School.