Going through a few old things, I came across a couple of points where the schism between the Ork & Dwarf elements in the Underground resulting in the expulsion of the Dwarves from the system was mentioned.

Has the reason ever been mentioned somewhere? Anyone know the cause, etc.?

I believe the novel Lucifer Deck is the source of that fact, but I'm not entirely sure; I know that Lucifer Deck [despite it's flaws] has a fair amount of detail on the Ork Underground.

First mentioned in the original Seattle Sourcebook, the Tacoma District regarding the Wall - a memorial to the victims of the Night of Rage. Other ork underground stuff is explored in the Downtown section and also used as location in the novels Into The Shadows (last chapter), Never Trust An Elf, and Shadowboxer (I think - recent memory is fuzzy). There's also some stuff about another section of the ork underground in the scenario DNA/DOA.

Boy do I now feel old.

Nifty. I don't have access to the Lucifer Deck; does it say what caused the Dwarf/Ork split? That's pretty much what I'm looking for.

Short tempers?

Too many lost basket ball games?

p. 58, New Seattle. Check out Mogar's comment.

Don't have New Seattle where I am right now. Anyone kind enough to help me out?