Michigan Compiled Laws, Chapter 31. Succession to Office § 31.2

(a) “Unavailable” means that the lawful incumbent of the office, including any deputy exercising the powers and discharging the duties of the office because of a vacancy, and his duly authorized deputy are not available to exercise the powers and discharge the duties of the office.

(b) “Disaster” means an extraordinary misfortune caused by an enemy attack upon the United States or by civil disorder and resulting in widespread destruction of life and property.

(c) “Enemy attack” means any attack or series of attacks by a power hostile to the United States which causes or may cause death, injury or substantial damage to the people and property in the United States by sabotage, or by the use of bombs, missiles or shells, or any other weapons of conventional, atomic, radiological, chemical, bacteriological, biological or any other nature, process or means.

(d) “State executive officers” means the elected heads of the principal departments of this state.

(e) “Emergency interim successor” means a person designated pursuant to this act who, in the event the incumbent or his deputy is unavailable, is to exercise the powers and discharge the duties of an office until a successor is appointed or elected and qualified as may be provided by law, or until the lawful incumbent or his deputy is able to resume the exercise of the powers and discharge of the duties of the office.

(f) “Deputy” means any deputy, assistant or other subordinate officer, authorized pursuant to law to exercise all of the powers and discharge the duties of the office.