Kaz was Lisbeth's husband. He had three sons with her. While he was on work on the wall during sunset, skimmers started attacked and he was killed. Dirk took over the leading role in the family after his father's passing.
While he was alive, Kaz had worked on Southwall, helping strengthening and thickening it. Kaz had been considered the leading role in their family then. When he died, the oldest son, Dirk took over the leading role in the family. Kaz was presumably a natural leader, and brave, strong and good-natured, qualities that his son Dirk also happens to possess.