Sec. 19-14. Openings; Permit Required:
   (a)   No person shall construct or maintain any openings or stairways in any public street or sidewalk or alley without a permit from the director of public works.
   (b)   All such lawfully maintained openings shall be guarded by a suitable strong cover or railing, to the approval of the director of public works. (M.C. 1963, § 11.114)