Answer:
To show the first human failure that contributed to the spread of the fire.
Step-by-step explanation:
"The Great Fire" by Jim Murphy is children's story about the 'Great Fires of Chicago' that burned down almost half of Chicago.
Jim Murphy started the story with the fire and then proceeded to tell of how the families were. By starting the story in medias res, he brings to the point the failures of humans that eventually led to the fire. Though the fire brought out the real issues of the families against each other, Jim didn't mention them before the fire. Instead, he focused on the fire first and then begins the background of the story.