Section 100. It is a matter of exceeding difficulty, if not one of impossibility, to lay down a general and definite rule respecting the liability of municipal corporations for the torts of their officers, agents and servants.

We are familiar with the principle that public quasi-corporations, such as counties, towns or townships, school districts and the like, being involuntary subdivisions of the state created for governmental purposes, are not liable for the torts of their officers and agents, unless made so by statute.

These public quasi-corporations, acting as agencies of the State, exercise governmental powers only, and hence their immunity from liability.

But a municipal corporation, as has been indicated, is of a two-fold or dual character or nature; in the one case it acts as an agent of the state, and is not subject to be sued for any act or omission occurring while in the exercise of any governmental power, unless by statute the action be given; in the other case it acts for the private advantage and benefit of the locality and its inhabitants, and is subject to the law like an individual or private corporation.

In the case of City of Galveston vs. Posnainsky, 62 Tex., 118, the court said: "Persons or corporations that voluntarily assume and undertake the performance of a work, even though it be quasi-public in its character, ought to be held to impliedly contract that they will exercise due care in its performance, and for a neglect in this respect should be liable for the resulting damages. We do not wish, however, to be understood to assert that there is a contract between the state and a municipal corporation accepting a charter, but simply to assert that, when such a corporation accepts a charter, giving defined powers, the law imposes the duty of faithfully exercising them, and gives an action for misfeasance or neglect in this respect to any person who may be injured by such failure of duty."1

It will thus be observed, that in determining the liability or non-liability of a municipal corporation for torts that, the nature of the duty performed is generally the determining factor.