(Longview, WA) -- A fire in a massive pile of wood chips at the Weyerhaeuser plant in Longview continues to burn, but officials say crews are making progress. The Longview Fire Department says a helicopter is assisting firefighters on the ground by dropping water on the chip pile. Heavy equipment is being used to separate the pile to get at the fire that's burning inside. Smoke continues to be an issue for the surrounding community. The fire started Tuesday night. The investigation into the cause of the fire is ongoing.