Failure of tailings dams often results in the release of substantial amounts of tailings into the environment, causing considerable damage. The flow of tailings presents a complex modeling challenge due to the free-surface flow and large deformations involved, rendering it intractable by conventional finite element or finite difference methods. A mesh-free formulation, based on smoothed particle hydrodynamics (SPH), was utilized to back-analyze documented tailings dam failures. As with any numerical model, the calibration of model parameters to corresponding physical quantities is a requirement prior to any application of the model. In addition to the effect of model parameters, such as the roughness of terrain, that are hard to quantify, the capabilities and limitations of the SPH model itself were investigated using a simple experimental flume flow setup. In this paper, the calibrated model was applied to literature-reported tailings dam failures. The outflow of tailings interacting with the terrain resulted in good agreement between the simulation results and the reported cases, enabling use of the modeling approach to assess the potential damage caused by tailings dam breaches and to predict flow paths of tailings.