Unless a governing body of the incorporating unit authorizes the execution of agreements regarding real property in the name of a commission as provided in section 11, all claims that may arise in connection with a housing project or projects shall be presented as are ordinary claims against the city or village. Written notice of all claims based upon injury to persons or property shall be served upon the city or village clerk within 60 days from the happening of the injury. The commission may dispose of claims in its discretion. The cost of investigation, attorneys’ fees, all claims that may be allowed, and final judgments obtained from those claims shall not be a general obligation of the incorporating unit and shall be paid only from the operating revenue of the housing project or projects or from the proceeds of liability insurance. This section does not preclude the incorporating unit or commission from asserting a defense of governmental immunity to which it may be entitled under law against any claim made against the incorporating unit or the commission.