I see there was a Michel Bluemke born 1850 in Germany who immigrated 1873 and lived in Detroit ward 13. Maybe this would be some clue? I checked the page before and the page after but did not see Kruegers living near him.

Regarding the Krueger couple can you give more detail such as if you found them on a census and where were they living. When were they living in Detroit? Also if you can list the names of their children that would help.