A peat dike in The Netherlands unexpectedly failed at the end of the dry summer of 2003. The failure mode was not a Bishop type circular failure used in routine dike stability analyses in The Netherlands. The failed dike segment was displaced horizontally over 6 m The failure plane was found to lie at the boundary between peat and the underlying sand. It was concluded that failure was caused by a chain of events in which weight loss and shrinkage of the peat, due to the dry weather conditions, are considered important factors. Analyses of the behaviour of the peat made clear that several processes, controlled by hydrological conditions in the unsaturated and saturated zones in the embankment, resulted in fracturing of the peat. The fracturing along with a very high strength anisotropy of the peat resulted in a connection between the water in the canal and the water in the sand, raising the piezometric head in the sand by several metres, allowing the dike to simply 'float' away for over 5 m, pushed by the water in the canal.