Since your question is focused on getting your first, out of college, job as a structural engineer, I would suggest that you focus on being a very knowledgeable structural engineer. In my experience, companies that hire new engineers (civil, mechanical, electrical, etc.) want to hire new engineers that can go to work for them and become productive in the shortest time possible. After you are in the field for awhile, working as a structural engineer and you decide you want to get into the business end, you can get an MBA (that the company might even pay for) or you may decide that you want to get an advanced degree in engineering or who know what. I think that for an engineering student, get the very best grades you can and focus on your major, taking elective courses related to civil engineering. Given the safety aspects of structural engineering, it is hard for me to imagine that a structural engineering company would look for a new hire (that is also a new college graduate), inexperienced in structural engineering but has a minor in business. What does a minor in business due to enhance your engineering expertise during those first few years on the job? You having a minor in an unrelated subject, may cause the company to ask how committed you are to structural engineering.
Hope this helps,