This story says Florida based company then in the next paragraph says its based at Willow run.
http://www.annarbor.com/news/ypsilanti/ypsilanti-man-among-7-killed-in-afghan-crash/
Its obviously a global company so I’m guessing this particular plane or crew were Michigan based
Check the National Air Cargo website. http://www.nationalaircargo.com/default.aspx