On this day in 1871, flames spark in the Chicago barn of Patrick and
Catherine O'Leary, igniting a two-day blaze that kills between 200 and
300 people, destroys 17,450 buildings, leaves 100,000 homeless and
causes an estimated $200 million (in 1871 dollars; $3 billion in 2007
dollars) in damages. Legend has it that a cow kicked over a lantern in
the O'Leary barn and started the fire, but other theories hold that
humans or even a comet may have been responsible for the event that left
four square miles of the Windy City, including its business district,
in ruins. Dry weather and an abundance of wooden buildings, streets and
sidewalks made Chicago vulnerable to fire. The city averaged two fires
per day in 1870; there were 20 fires throughout Chicago the week before
the Great Fire of 1871.
