Mo. Rev. Stat. § 81.060
No action shall be maintained against any city or town organized and existing under special charter in this state, which city shall contain more than five hundred and less than three thousand inhabitants, on account of any injuries growing out of any defect or unsafe condition of or on any bridge, boulevard, street, sidewalk or thoroughfare, in said city or town until notice shall first have been given in writing to the mayor of said city or town, within ninety days of the occurrence for which said damage is claimed, stating the place where, the time when such injury was received, and the character and circumstances of the injury, and that the person so injured will claim damages therefor from such city or town.
§ 81.060, RSMo
RSMo 1939 § 7524