Mich. Comp. Laws § Article IV § 39: Continuity of government in emergencies.

Sec. 39.

In order to insure continuity of state and local governmental operations in periods of emergency only, resulting from disasters occurring in this state caused by enemy attack on the United States, the legislature may provide by law for prompt and temporary succession to the powers and duties of public offices, of whatever nature and whether filled by election or appointment, the incumbents of which may become unavailable for carrying on the powers and duties of such offices; and enact other laws necessary and proper for insuring the continuity of governmental operations. Notwithstanding the power conferred by this section, elections shall always be called as soon as possible to fill any vacancies in elective offices temporarily occupied by operation of any legislation enacted pursuant to the provisions of this section.