It was caused by a failure to connect the freight train's brakes correctly due to human error.

The 19:31 freight train from Ellesmere Port to Mold Junction consisted of 38 wagons hauled by a Class 24 diesel locomotive no.

They rescued a trapped postal worker and evacuated several passengers from an adjacent lightly loaded train before it was engulfed in flames.

Damage caused to the trains was severe, especially after petrol from two of the tank wagons began to boil and was forced out of the pressure relief valves, whereupon it ignited.

As the extra brake power was not available on the falling gradient into Chester, the train was unable to stop as it entered the station.