On Saturday 13 June 1992 two of three spans of a masonry viaduct at St John’s Vale Station, Deptford, collapsed during a pause in demolition work. Two men were killed, buried under the fallen spans, and several others were injured as they descended on top of the debris. The collapse was of the ‘domino’ type and was described in New Civil Engineer as unexpected. Both the BBC and Grampian Television reported an apparently similar collapse in Aberfoyle, near Balmoral, in 1989. In both cases the structure collapsed when the crown of one span had been partly cut away. This feature, while prompted by these two failures, is not intended to present a detailed explanation of them. In the case of the Deptford failure particularly, only very limited information is available.