An elective office becomes vacant: (1) Upon the incumbent’s (a) death, (b) adjudicated incompetence, or (c) recall from the office; or (2) Upon declaration by the council of a vacancy in case of the incumbent’s (a) failure, following election or appointment to the office, to qualify for the office within ten days after the time for his or her term of office to begin, (b) absence from the city for over 30 days without the council’s consent or from all meetings of the council within a 90 day period, (c) ceasing to reside in the ward from which elected, (d) ceasing to be a qualified elector under state law, (e) conviction of a public offense punishable by loss of liberty, or (f) resignation from the office.