HONOLULU (KHON2) -- The Honolulu Fire Department has not been able to determine the cause of a house fire that occurred in Waimanalo at 2:46 a.m. on Dec. 21. Get Hawaii's latest morning news delivered to your inbox, sign up for News 2 You The building was abandoned, with the fire originating from a lumber pile in the living room. Honolulu Fire offers holiday safety tips It is currently unclear how the lumber pile was ignited. Find more Hawaii, Oahu, Maui and Kauai news here The fire was fully extinguished less than two hours after the initial 911 call. There were no occupants at the time of the fire, and there were no injuries reported.