When any lot, or premises, building or structure within the city, because of age or dilapidation, the accumulation of refuse or debris, the uncontrolled growing of noxious weeds, or because of any other condition or happening becomes, in the opinion of the Council, a public nuisance, or hazard which is dangerous to the health, safety or welfare of the inhabitants of the city or of those residing or habitually going near such lot or premises or such building or structure, the Council may, after investigation, give notice to the owner or owners of the land upon which such nuisance or hazard exists or to the owner or occupant of the land or the building or structure itself, specifying the nature of the nuisance or hazard and requiring such owner or occupant to alter, repair, tear down, abate, or remove the nuisance or hazard within a time to be specified by the Council which shall be commensurate with the nature of the nuisance or hazard. Insofar as practicable, considering the nature of the nuisance or hazard, the notice herein required shall be in writing and delivered in person or by registered letter, return receipt requested, with full postage prepaid thereon, addressed to the address set forth in the current assessment roll of the city or the records of the Assessor. Such notice shall be given by the Clerk. If, after diligent and reasonable effort to locate the owner of the premises or his agent, he cannot be found, such notice shall be given to the occupant of the premises, if any, and by posting upon the premises in plain view of all persons going upon or passing near such premises. If, at the expiration of the time limit in said notice, the owner has not complied with the requirements thereof, or in any case where the owner of the land or of the building or structure itself is not known or cannot be found, the Council may order such nuisance or hazard to be abated by the proper department or agency of the city which is qualified to do the work required, or may do the work by contract or by hire, and the cost of such abatement may be assessed against the lot, premises, or description of real property upon which such nuisance or hazard is located, by special assessment.