It just doesn't happen ...
Oh man how did that happen:eek:
It just doesn't happen. City rails are well controlled and segmented from other rail systems, there's no reason for it.
Except human error or track tampering. In this case, one train rammed into another from the rear. Absolutely no reason for that to happen.
Text messaging is my first instinct. I'm sure this will bring about a banning of cell phones on your person if that is the case.
Here's a map of the DC metro system. It happened on the Red Line as I understand it:
http://www.wmata.com/rail/maps/map.cfm
Again, metro transit is very safe. The chance of accidents are extremely small, unless cars also share the same areas (light right run down the middle of roads, with intersections/turn lanes near them). That's not the case in DC, which is almost always (or always?) segmented. I haven't seen a road crossing on the DC Metro system yet, but there may be a few.