Something confuses me about Resident Evil 2's ending

[voltz]

I just want to ask, how far down is it when they reach the hive lab in both games and when they escape the place, how the hell are they back at ground level?

There isn't at any point that I know of where they do ascend to get back to the surface. The train that leads them out is so far underground and just heads straight out. The first game shows them reach outside and I assume the same can be said for the remake since they don't exactly show them getting outside. Is Raccoon city in a location that's well elevated or something??