Not surprising that there would be rocks on the track. While not a big quake in the great scheme of things it's good-sized for the area, and it and the aftershocks so far are very shallow - practically at the surface. Wouldn't be surprised if some minor ground rupture is found by daylight.

Besides the railroad - somebody's probably checking the DAM (and a couple of others nearby) given how close the main and aftershocks are. Did You Feel It reports intensities of VI-VII near the center, which translates to light-moderate damage, but that's not heavily populated country.