Sec. 2.15  City liability.
   The city shall not be liable for damages sustained by any person either to his person or property by reason of the negligence of the city, its officers or employees, nor by reason of any defective condition or of obstruction in any public place unless such person shall serve or cause to be served upon the clerk, within sixty days after the injury resulting in such damage shall have occurred, a notice in writing, which notice shall set forth in detail the time, place and cause of the injury, the manner in which it occurred, the extent of such damages as far as the same have become known, the names and addresses of the witnesses known at the time by the claimant and a statement that the person sustaining such damages intends to hold the city liable for such damages as may have been sustained by him. All claims, whether arising out of contract or tort, shall be made under oath and shall be filed with the clerk for consideration by the council after the cause of action has arisen.
   It shall be a sufficient bar to any action upon any such claim that the notice of injury and the verified proof of claim required by this section were not filed within the time and in the manner herein provided.