The Canadian government said "ooooooshit" and ordered a massive review of anything they could find that was related to the phenomenon and the American rails before doing one damn foot more of work.

... actually, that's not true. I bought a book on the building of Canada's transcontinental railroad last year. I haven't read it yet. I'll figure out what happens to them once I have, but I'm pretty sure it'll come back to what I said above.