The regular phone lines are running through the same cross-country fiber as everything else. There's only one phone network. All voice and all data runs through the same pipes.
Yes, there are many bypass lines that run around all over the place, and they do bypass the major chokepoints. But... and it's a big but... those circuits can only handle a fraction of the traffic of the main pipes. If the main line is lost, some traffic will be routed around it, but at only a fraction of the bandwidth. Once congested, those lines may as well be down.
It happens all the time, really. Whenever even one of the last-mile providers like Qwest has a fiber cut someplace... it causes massive congestion on the net writ large.
Interesting. Sounds like you do have a novel script there! :) What could be done to safeguard against that type of thing, then?