Gosh, yes - keep it. If you don't want the "tunnel", it's still an already-built area that can be closed/re-imagined.
BTW - someone referred to running tracks through a building as "goofy" well, no it isn't, especially in the time before the US was de-industrialized, and had so many crowded urban/industrial areas - everywhere. Now, I'll admit, it is less common, but not un-common.
