If any person, persons or corporation holds a mortgage or lien in an amount more than double the assessed value of any residential property upon which there exists a nuisance as defined in this chapter, such mortgage holder or lien holder shall likewise have the duty to abate such nuisance, but such duty shall arise only upon written notice to the mortgage holder or lien holder. The failure to abate such nuisance after written notice shall make the mortgage holder or lien holder liable in the same fashion and to the same extent as the property owner. (Ord. 158 § 4, 1951).