ever seen this?

I was putting a new cassette on the dos this morning and while pulling the old cassette off, the cassette body of the hub literally came apart in my hands! What the f? I'm not sure what was holding it on in the first place but its not there now. Anyone ever have this happen before??? I guess the wheel will be going back to Bikeman tomorrow and hopefully they can figure out what happened. Looks like I won't be riding the niner for a bit.