Upon the application of a member or his or her department head, a member who has ten or more years of credited service and becomes totally and permanently disabled for duty in the employ of the city as a result of causes not occurring in the course of his or her actual performance of duty in the employ of the city, may be retired by the board, provided, that after a medical examination of the member, made by or under the direction of the medical director, the medical director reports in writing to the board that:
   (a)   The member is mentally or physically totally disabled for duty in the employ of the city; and
   (b)   The disability will probably be permanent.
(1957 Rev. Ords., § 2.523; 1992 Code, § 35-35)