It shall be the duty of any police or health officer, upon learning in any way whatsoever of the existence of one or more of the unlawful conditions described in Section 8.12 .010, to notify the offender in writing to remove or abate such unlawful conditions, stating the shortest reasonable time for such removal or abatement. In the event of the refusal or neglect on the part of the notified offender to obey such order, the chief of police shall, and he is authorized and directed to do so, forthwith remove and abate such unlawful conditions – and he shall keep an accurate account of the cost and expenses thereof, which shall be paid from the city treasury, and such cost and expenses may be recovered from such offender at the action of the city in any court of competent jurisdiction, or the amount thereof may be, by ordinance of the council, declared a lien, as and for the cost and expenses in the abatement of a nuisance, against the property from and upon which such unlawful condition was so removed and abated. (Ord. 497 §2, 1914)