Crisis is sometimes the catalyst for succession in a family business. For hardwood and softwood manufacturer Chisholm Lumber, unexpected adversity sparked leadership changes from one generation to the next not once, but twice. Both times, the descendants rose to the challenge and kept the 168-year-old enterprise running. The first emergency-driven transition happened in 1980, when a fire destroyed Chisholm’s major manufacturing facility in Roslin, Ont., between Toronto and Ottawa. …Doug Chisholm of the fifth generation was 33 at the time, in Toronto working in consulting, but he didn’t want the family business to dissolve. …He and two cousins wanted to keep the enterprise running. “I said, ‘Let’s see what happens in five years,’” says Doug, now 77. “Well, we never left.” …Doug’s son, Peter, 46, returned to Roslin in 2007 to join Chisholm, backed by a McGill University economics degree and a stint in sales at a foreign company in Ottawa. Two of his cousins joined him. [A Globe and Mail subscription is required for full access to this story]