Most "accidents" are caused by carelessness, stupidity, recklessness and overweening confidence, not misfortune. Driving recklessly, especially while ratrunning through residential areas, is quite as criminal as dropping a concrete block from a bridge. The only difference is that one criminal hopes to cause damage, and the other hopes he/ she will not cause damage (especially to their own vehicle), but takes no care to justify that hope.

But as I pointed out earlier, attacks of this nature on trains are a very frequent occurrence. it's only the underlying intrinsic safety of the railways that makes them survivable.