Mo. Rev. Stat. § 622.540: Exemption from liability of a carrier by contract or regulation.

That no contract, receipt, rule, notice or regulation shall exempt any railway company, or corporation, express company or corporation or any other company, corporation or common carrier, engaged in the transportation of persons or property, from the liability of a common carrier, or carrier of passengers, which would exist had no contract, receipt, rule, notice or regulation been made or entered into.