Source: Remembering the Great War by the WR Record Dead link.
Family Search: When Private John Gerbig was born on 4 October 1887, in Berlin, Waterloo, Ontario, Canada, his father, Conrad George Gerbig, was 26 and his mother, Clara Kriwinski, was 22. He lived in Waterloo, Ontario, Canada for about 10 years. He registered for military service in 1914. In 1914, at the age of 27, his occupation is listed as electrician, lineman in Berlin, Waterloo, Ontario, Canada. He died on 20 December 1915, in Voormezele, West Flanders, Belgium, at the age of 28, and was buried in Voormezele, Ieper, West Flanders, Belgium.
History of the 18th Battalion CEF, "The Fighting Eighteenth" 