If, at any time, any building or land in existence or maintained at the time of the adoption of this ordinance which does not conform to the regulations for the district in which it is located shall be destroyed by fire, explosion, act of God or act of the public enemy to the extent of 50 percent of its value as determined by three (3) competent appraisers, then and without further action by the Town Council, the said building and the land on which said building was located or maintained shall, from and after the date of such destruction, be subject to all the regulations specified by this Code for the district in which such land and building are located.