It is a general principle, of very wide application, that a municipal corporation, in the absence of a statute, is not obliged to undertake the execution of governmental functions respecting the health, peace or property of its citizens. Nor is such corporation liable for the insufficient or negligent execution of such functions in case it undertakes to perform them. The ground of this exemption is that the municipality, in these matters, exercises discretionary powers conferred upon it by the state, and acts, not for itself in its corporate capacity, but for the general public as an agent of the central government.
Sunderland, Edson R. "The Liability of Water Companies for Fire Losses." Mich. L. Rev. 3 (1905): 442-457.