Mo. Rev. Stat. § 537.165

Every county, city, town, village, fire district or other political subdivision of the state having a full time salaried fire department shall defend, in the name and on behalf of the members of its fire department in any action brought against a member involving claims for death or injury to persons or property arising out of their operation of motor vehicles of the fire department in the performance of their duties. Such defense shall be conducted by the regular legal staff of the county, city, town, village, fire district or other political subdivision involved. No judgment, or liability for court costs, obtained against any such member in any such action shall be a liability of the county, city, town, village, fire district or other political subdivision defending such action.