(Portland, OR) -- The burned-out Centennial Mills building in Northwest Portland will begin to come down on Monday. There are concerns the weakened building could still collapse on its own. Explosives will be placed under the metal water tower at the top of building which are expected to bring that structure down. It's unknown if some of the walls will also come down. Crews spent Sunday dampening the area with water to limit dust and debris. Residents in the area were warned of the planned explosions.