K.S.A. 66-232

In all actions against any railway company organized or doing business in this state, for damages by fire caused by the operating of said railroad, it shall be only necessary for the plaintiff in said action to establish the fact that said fire complained of was caused by the operating of said railroad, and the amount of his damages (which proof shall be prima facie evidence of negligence on the part of said railroad): Provided, That in estimating the damages under this act, the contributory negligence of the plaintiff shall be taken into consideration.