Be it further enacted, that the city manager may appoint a fire marshal or designate a member of the fire bureau whose duty shall be, subject to the chief of the fire bureau, to investigate the cause, origin, and circumstances of fires and the loss occasioned thereby, and assist in the prevention of arson. (As amended by Priv. Acts 1972, ch. 416, sec. 18 and Priv. Acts 2014, ch. 55, sec. 1)