Originally Posted by
happypills
Were you using a proper lock ring tool?
The damage looks like something struck and cracked the threaded part of the hub apart....
Were you trying to chisel on/off the cog with hammer and chisel when you accidentally slipped then slipped and landed a blow on the threads (assuming you already had gotten the lockring off, exposing the threads)?
There's some spoke damage, so I'm inclined to believe this happened while the bike was in motion, and the chain went into the spokes. I just can't figure out how/why.