If a nonconforming structure or a structure occupied by a nonconforming use is destroyed by fire, the elements or other cause, it may not be rebuilt except to conform to the provisions of this Ordinance. In the case of partial destruction of a nonconforming use not exceeding sixty (60) percent of its reasonable value, reconstruction may be permitted after a hearing and favorable action by the City Council, but the size and function of the nonconforming use shall not be expanded.