At all times from the commencement of the work until the completion thereof and the restoration of the street or alley to its original condition, the person making such opening shall erect and maintain suitable barricades around the same so as to prevent pedestrians and other persons and vehicles from entering the area immediately adjacent to and surrounding such opening, or shall, if entrance to the area is allowed, cover such openings so as to protect persons and vehicles from injury or damage, and shall at all times during the hours of darkness maintain suitable warning lights thereon. Such barricades and warning lights shall be of such type and character and shall be so located as to reasonably protect persons and property from injury or damage as a result of the existence of such opening, and shall be placed and maintained in a manner reasonably acceptable to the Superintendent of Public Works. (Ord. 315, 11-8-65)