(South St. Paul, MN) — Fire officials say a fatal South St. Paul house fire that resulted in the deaths of a father and his two sons was likely caused by food preparation activities in the home’s attached garage. The father, Soeun Sem was known to make food and propane fire cooking equipment was found in the area where the fire originated on October 13th. Investigators also determined the overhead garage door and doors between the garage and the house were open at the time of the fire and likely contributed to the rapid spread of smoke and fire from the garage to the living area of the house. Officials say all three victims died as a result of smoke inhalation – high levels of carbon monoxide were present in all three victims. While there were working smoke detectors in the home at the time of the fire, it is probable that thick smoke and high heat conditions prevented the escape of all three victims from the second story of the home.