I have no idea who exactly did that mess; it's a sufficiently old construction that there's some chance that the specific person is long dead and that none of the subsequent owners really understood how dangerous that was. I have a feeling that the very leakiness of the house was saving the residents thereof from gassing themselves to death from this thing and from the leaky gas furnace.

I would be less worried if I hadn't had to spend that $15K premium to actually buy the house; had I gotten it for my original bid, I'd have that $15K now to do repairs more quickly rather than having to spread it out over time.