When a nonconforming building or structure is destroyed or partially destroyed by fire, explosion, or other disaster, or is otherwise damaged to the extent of 50% of the appraised replacement value of such building or structure, such nonconforming building or structure shall not be restored, or rebuilt, except in such manner as to conform to the regulations of this Ordinance, and amendments thereto. When a nonconforming building or structure is partially destroyed by fire, explosion, or other disaster to less than 50% of its appraised replacement value, it may be restored to its original use in accordance with provisions of this Ordinance but must be restored within one year of such happening.