Regardless of the quality of journalism on Yahoo, that's exactly the same story I've been hearing on various radio stations here.
However, North Korea seems to have imposed a news blackout, so we'll probably never know for sure.
The point about a backlog of trains after the private train went though is a good one, and I never would have thought of it.
Sadly, another comment I heard on the radio is that North Korea's medical system will probably be overwhelmed initially by a disaster of this magnitude. They may not be keen on asking the International Red Cross for assistance either.