There's an obituary for a Charles Lützow (1878) published in Milwaukee's German newspapers. He committed suicide, leaving a wife and 2 children. There are followup clippings detailing the coroner's inquest. His name is spelled "Lütelzow" in the initial article, and then corrected in the following clippings.
There are also entries for a Charles Luetzow (1923), and a Carl (1889) found in "Milwaukee's German Newspapers; an index of death notices and related items" (1844-1950).
Any research on this surname should take into account both spellings in any 19th or early 20th c. firstname.lastname@example.org
Indexing Milwaukee's German newspapers continuously since 2007 and beyond 2014.