If at any time, any building in existence on the effective date an area is zoned or rezoned under Chapters 20.02-20.60 which does not conform to the regulations for the district in which it is located, be damaged or destroyed by fire, explosion, act of God, or act of the public enemy, to the extent of more than fifty percent of the market value thereof, according to the appraisal by the county assessor for the fiscal year during which such destruction occurs, the land and building shall be thereafter subject to all the regulations specified by Chapters 20.02-20.60, for the district in which such land and buildings are located.
(Ord. 67-10 § 5.0203, 1967.)