The root cause was the lack of supervision by railway authorities, who tolerated so many stowaways riding on the train. Contributing factors were the low-quality coal, the lack of ventilation in the tunnel, the wet rails, and the fact that the train had a double heading instead of a push–pull configuration.[1] The lack of communication between the drivers of the two locomotives was the eventual trigger factor. In addition, the death toll was aggravated by the delay in rescue efforts.