What caused the train wreck at Montparnasse in 1895?

This incredible photo of the wreck at Gare Montparnasse in Paris shows a very dramatic scene of a train that has crashed through the wall and partially tumbled to the street. The cause? Both mechanical failure and human error. The train was late, so the driver had it pull into the station at a high speed. It had two different types of braking systems: handbrakes and an air brake known as a Westinghouse brake. The conductor realised that the train was going too fast and applied the Westinghouse brake, however it didn’t work. He then waited too long to use the handbrakes, which weren’t sufficient due to the weight and speed of the train. The locomotive crashed through a wall and the first few cars fell towards the street below. Amazingly, only a few passengers and train employees were injured, though one pedestrian on the road below was killed.

Answered by Shanna Freeman.