You can be critical of the parent company's competence and Romney's qualifications to actually run a company, but ethics had nothing to do with the problems in this case. Here's a link to a Reuters article, giving a fairly good account of the many problems with the company.
It's a bit sappy on the personal stories of workers, but gives some information on the multiple reasons for the eventual failure.
GS Industries
Watch the video in post 19.
Are you actually telling me that it's ethical to get a $180 million loan on a $30 million company's assets and then strip the company? *sigh*
Romney needs to answer some questions.