Reconstruction of damaged building or structure. A nonconforming building or structure, or any building or structure containing a nonconforming use wholly or more than 50% destroyed by fire, explosion, flood or other phenomenon, or legally condemned, may be reconstructed and used for the same nonconforming use, provided that the reconstruction of the building shall be commenced within one year from the date the building was destroyed or condemned and shall be carried on without interruption. No further expansion of the original nonconforming use will be permitted.