The duties imposed upon owners of abutting property by the laws of this state and by this chapter shall at all times be exercised under the supervision and to the acceptance of the city engineer or his inspector. No work which shall create any obstruction to public travel shall be commenced until a permit therefor shall have been granted by said city engineer, and the owner of abutting property shall be liable for all damage which may arise by reason of carelessness in conducting any work upon the adjacent sidewalk, or by reason of lack of protection of the public from danger by proper guards or signals, either by night or day. (Ord. 1979, 2-9-1976)