Mid-July, a violent storm wreaks havoc on the fair. The wicked weather damages several of the fair's buildings and exhibits, including the hot air balloon that essentially disintegrates in the high winds. The next day, as Burnham monitors repairs, another fire breaks out in the Cold Storage Building. The fair's fire department responds, and several firefighters die as they become trapped on a tower. The day after the fire, fair attendance soars to over 100,000.
In response to the fire, the coroner orders an investigation, and Burnham is forced to testify in court. The jury charges Burnham with negligence, but the police are surprised by this and do not arrest Burnham. Upon return to the fair, Burnham takes extra precautionary measures in response to the fire. The fair's exposition directors give a committee power to oversee the reduction of fair spending. Yet again, Burnham is faced with another challenge in encouraging fair attendance as this committee scrutinizes his every move.
Daniel Burnham personifies innate goodness and determination. Despite major setbacks, Burnham remains steadfast in his commitment to do what it takes to make the fair a financial success.
In an example of irony, Burnham scours his brain to figure out what he can do to boost fair attendance legitimately; the tragedy of a devastating fire turns out to be the ticket to draw people to the fair. The social commentary makes a clear statement about what really motivates people.
Chapter 40 might be interpreted as a loose allusion to the classic story of The Wizard of Oz. Some of the images — the storm and the hot air balloon, in particular — are reminiscent of details within L. Frank Baum's children novel's, which was published in Chicago in 1900.