Use nonconformity. Any structure which is a nonconforming use according to the provisions of this chapter which is destroyed by fire, flood, wind, hurricane, tornado or other act beyond the control of man, to the extent of 50% of the assessed value of the structure or more, must be replaced within 24 months of the destructive incident. If within the twenty-four-month period the structure containing the nonconforming use is not rebuilt, the nonconforming use shall not be reestablished, and the property shall only be used for a conforming use.