A vacancy shall be deemed to occur in the Council upon and as of the time of the presentation of a resignation to the Mayor or the President of Council, the death of a Councilman, the determination by the Council that a member of Council ceases to possess or has violated any of the qualifications of the office of Council member, the removal of a Councilman as provided in Section 3.11 of this Charter, the forfeiture of office as provided in Section 3.02 of the Charter, or upon the recall of a Council member as provided in Section 15.04 of this Charter. Any vacancy in the Council shall be filled by a majority vote of the remaining members of the Council for the unexpired term. If the vacancy is not filled within thirty days after it shall have occurred, the power of Council to fill the vacancy shall lapse and the mayor shall fit it by appointment immediately following the expiration of said thirty days. Any appointee under this section shall qualify under the provisions of this Charter and shall hold office and serve for the unexpired term and until his successor is elected and qualified.