In The Johnstown Flood, how does the author develop the idea that people’s decisions to stay or to flee determined whether they lived or died? The Johnstown Flood by following one person—Gertrude—and her decisions and their effects by giving examples of several people who lost their lives after deciding to stay where they were by listing the cause of death of everyone who was lost in the flood by switching from scene to scene, showing the lives of different members of families