The older trains were not that difficult to derail, they did not have the weight of current locomotives.
small rails and light equipment were the norm in the 1890's, the picture does not provide enough info to see if it was narrow gauge tracks.
Seeing as the elephant died from this incident, it was probably hit head on to have killed it.
Or The elephant standing on the track would also have derailed the train and killed the elephant.
really not much of a story.