 The accident was never explained; the train ran through Grantham station, where it was scheduled to stop, and derailed on a set of points on a sharp curve at the end of the platform, which at the time had been set for a freight train.No reason was ever established as to why the train did not stop as scheduled, or obey the Caution and Danger signals.Rolt (1956) described it as "the railway equivalent of the mystery of the "Marie Celeste"".