A Leeds-to-Bristol night mail train crashed under the road bridge at Charfield station, South Gloucestershire on 13 October, 1928.
Rail archives show the train went through a red signal in thick fog.
Gas cylinders used to light carriages ignited on impact, and the ensuing fire hindered the identification of bodies.
Historian Ian Thomas, who has researched the crash, said the identities of the two small burnt bodies would probably always remain a puzzle.
Source/Attribution
'Mystery of train death children'; BBC News, October 13, 2008, news.bbc.co.uk
Added Tue, Aug 31 2010 at 8:47PM UTC by