The fragmentation of storage tanks or other equipment of the process industry, for example caused by boiling liquid expanding explosions (BLEVEs), and the consequent missile generation is a problem in industrial safety whose importance is underlined by accidents such as that of Mexico City. It is inscribed in what is called the "Domino Effect". A method is presented to calculate the trajectories of missiles from horizontally mounted cylindrical vessels using analytical solutions of the equations of motion. The principal input parameters of these equations, e.g. drag and initial fragment energy, are stochastic or uncertain. Hence, they are represented by statistical distributions, whose parameters are determined as far as possible from experimental results or findings from past accidents. If no such evidence is available, reasonable assumptions, e.g. constant probability density function, are made. The Monte Carlo method is used to propagate the effect of the stochastic and uncertain input parameters through the calculation. Numerical results thus obtained are compared with evidence from accidents.