It is unlawful for any person to excavate or cause to be excavated any hole, trench or ditch in any street, alley or sidewalk within the City limits of the City without maintaining barricades on such hole, ditch or trench with adequate lights and other warnings to the public of the location of such hole, trench or ditch. All such excavations shall at all times be safely guarded against the possibility of persons, vehicles or animals or other property being injured by the same. (Ord. 1205 § 2, 1969; prior code § 27.602(3)).