Without a doubt, the Great Chicago Fire was one of the worst disasters of the 19th century. It leveled more than 3 square miles of the city, killing 300 people and leaving another 100,000 homeless. But for nearly a century and a half, questions have lingered over who—or what—actually started the fire on this day, Oct. 8, in 1871. The debate has featured a rotating cast of colorful (possible) culprits, but every explanation has its doubters. To this day, no one knows for sure which, if any, is to blame. The suspects include:
Mrs. O'Leary and her cow. That the fire started in the barn behind Catherine O'Leary's West Side cottage is certain. How it started is the question, although throughout her life, O'Leary suffered the condemnation of a city that blamed her for it. As the popular story went, O'Leary was in the barn around 9 p.m., milking her cow, when the cow kicked over a lantern and sparked the inferno. According to the Chicago Tribune, O'Leary herself consistently denied this account, saying that she never milked after dark. However, as an Irish immigrant living in poverty, she made a convenient scapegoat—and reporters seized on the fire's great irony: Although it decimated Chicago's downtown, wiping out the central business district and charring the courthouse, the blaze that began in her barn somehow spared O'Leary's meager cottage.