15 ILCS 505/16

In case of the death of the Treasurer, it shall be the duty of the Governor to take possession of the office of such Treasurer, and cause the vaults thereof to be closed and securely locked, and so remain until a successor is appointed and qualified; and at the time such successor takes possession of the office, he, together with the State Comptroller and any of the bondsmen of the deceased Treasurer who shall be present, shall proceed to take an account of all the moneys, papers, books, records and other property coming into his possession; and the Comptroller shall take of such succeeding Treasurer his receipt therefor, and keep the same on file in his office.