Wow, only 60km/h.

If it was a modern bus hitting a building at that speed, most occupants would be able to walk out. Really puts into perspective how much safety improved in the past 100 years.

One of the issues is that the body consists of a wooden frame, surrounded by a thin sheet of steel to avoid extra weight. So it's not very strong, plus the bulk of the 14 ton mass lies on the bottom where the bogies are. When it derailed and tipped over, the strong structure underneath the cabin sort of crushed the lightweight structure where the passengers were.

Passenger cars from 40 years ago would struggle to protect you at those speeds.