It's not a question of something wearing out under normal processes - it is something that was not assembled correctly and damage resulted riding it that way. No way you could know that there was something wrong. Not saying it necessarily is the crank-bottom bracket interface but symptoms do point that way.
Thanks, Jur. Yeah, I understand--looking through all the forums I agree the symptoms are most likely there. We'll see what Peter has to say. Now the long wait--this was my one functional bike!