[Drago]

Photo #1 in this slideshow seems to show that: http://www.myfoxphilly.com/slideshow?widgetid=156171&slideshowimageid=1

[Cementjungle]

Looks like something knocked that first car (the engine?) off the track.

No sign of anything it might have hit on the track (freight car, etc).

I wonder where the engineers are? No one has mentioned them, and they would have been right there in the front.