Chicken or Egg?

As in which came first? Did the train stop running because they tore up the tracks, or because the mechanic's Rube Goldberg repairs and additions wore it out?
Up in Sebastopol, CA for Jackie's 80th birthday do. It's been a "soft day" as the Irish are alleged to say, since we landed in Oakland. It's really green up here at this time of year though - a different kind of beautiful from home in Chandler.