This could get weird.
That’s what “emergency recall” procedures and cooperative agreements are for. If Philly can’t find enough guys to fix this, I would think that available workers from nearby cities could be there in a couple of hours at most to help out. Plus, there are likely Army Corps of Engineers units not too far away. A four-foot main is not the kind of thing that can be handled by the second-string crew.
The Schukyll Expressway once had an entire section of highway heave about three feet up in the air from extreme heat. Coolest thing I ever saw. It wasn’t a slow process. It just launched.