Rerouting was so doable decades ago. I remember on IC's 'Land O-Corn' (a Chicago to Waterloo, IA train) when a freight derailment near Jessup, IA caused us to be rerouted via Oelwein, a Chicago Great Western hub. Sadly the only track to Oelwein today is from Waterloo, with nothing in Oelwein toward the NNW (Minneapolis), ESE, etc. East Palestine, OH was on the PA RR's mainline to Chicago and wide owing to multiple tracks. Plenty of lines and plenty of tracks and dozens of RRs was the situation. Watertown, SD had at least four RRS and more tracks (like spokes on a wheel) with C&NW, CRI&P, GN, and Minneapolis & St. Louis lines from numerous directions. All had passenger train service, though that gradually waned, so by the 50s little remained though the tracks were handling freight (I rode in the caboose part way on the Watertown to Sioux Falls line, only the southern piece of which is still in place today). I remember seeing the Wentworth, SD "union" depot where my mother in the 1920s changed trains from the GN to the CMSP&P to reach summer school in Madison, SD.