Mich. Comp. Laws § 211.501

Sec. 1. Whenever any parcel of real estate shall have been assessed by the proper body for the construction of any public improvement, and such assessment has not been paid and cannot be lawfully made a lien on the real estate, the amount of such assessment shall constitute a personal obligation against the owner of such real estate, and may be recovered in a suit in assumpsit against said owner, before any court of competent jurisdiction, maintained by the officer in whose hands the assessment roll shall have been placed for collection.