Simulation studies are often used to examine the operational behaviour of distillation columns, but they have found little or no use in safety related studies. A rigorous model for the simulation of the dynamic behaviour of distillation column has been developed. This model allows the analysis of the influence of different disturbances (failures) on the dynamic behaviour of a methanol/water column. Disturbances of the cooling medium supply to the condenser and the reflux stream have been examined. In this paper only the results of the simulation for a failure of the cooling water supply are presented and discussed. Initial experimental results, which should help to corroborate the simulation results are also presented.