Whenever any sidewalk elevator door or other sidewalk opening equipped with a door
or a cover in the public sidewalk is open, such opening shall be protected by guards,
approved by the city engineer, not less than 32 inches in height, and fully protecting
all sides of the opening; provided, however, that the guard on the loading side may
be removed therefrom during the period of active loading and unloading and while one
or more persons are present.
