Watch the special Denver Post documentary, “The Fire Line: Wildfire in Colorado.”

Four times in four years, wind-fanned flames raced through Colorado neighborhoods in and at the edge of dying forests, killing people and breaking records for destruction. And because more than 100,000 people in the last decade have moved into “red-zone” areas primed for conflagration by a century of fire suppression, no one is sure that the devastating fires of 2012 and 2013 will not be repeated.