Whenever the inspecting official determines that any structure in the city is an imminently dangerous structure, he shall notify the owner of said structure by any reasonable means, including telephonic means, and allow the owner a reasonable period of time, as determined by the inspecting official, in which to make the structure safe or to commence and complete demolition of the structure. Upon the failure or refusal of the owner to make the structure safe or to commence or complete demolition within the time period provided, the inspecting official shall proceed at once to make safe the structure or to demolish the structure.  In the event the work is performed by the city, the costs of same shall be assessed against the property.  (Ord. 84/T-3098).