The Harrow and Wealdstone rail crash was a major railway disaster and collision on the British railway system on 8 October 1952.

The accident

Accident

An accident or mishap is an unforeseen and unplanned event or circumstance, often with lack of intention or necessity. It implies a generally negative outcome which may have been avoided or prevented had circumstances leading up to the accident been recognized, and acted upon, prior to its...

 took place 11.5 miles (18.5 km) from central London. The crash was the worst railway disaster in England and the worst peacetime railway crash in Great Britain, surpassed only by the 1915 accident at Quintinshill, Scotland, in which a troop train collided with a stationary passenger train and another express train

Express train

Express trains are a form of rail service. Express trains make only a small number of stops, instead of stopping at every single station...

 ran into the wreckage.
The crash, which took place at 08.19, was a double collision involving three trains.