Mich. Comp. Laws § 31.6
If any state executive officer is not able or is unavailable to exercise the powers and discharge the duties of the office because of a disaster, the legally authorized deputy of the officer shall exercise the powers and discharge the duties of the office. If the deputy is not able or is unavailable to exercise the powers and discharge the duties of the office because of a disaster, the available emergency interim successor, highest in order of succession, shall exercise the powers and discharge the duties of the office. The emergency interim successor shall exercise the powers and discharge the duties until a new officer is appointed or elected and qualified or the regular incumbent of the office or his deputy again becomes available to exercise the powers and discharge the duties of the office.
MCL 31.6