At 9:00 PM on October 8th, a fire erupted in a small barn belonging to the O’Leary family. The cause of the fire remains unknown, although a popular theory suggests that an O’Leary cow knocked over a lantern. Chicago had been experiencing a severe drought, and over 70% of the city’s buildings and sidewalks were constructed from wood. Additionally, the roofs of these buildings were highly flammable.

The fire spread rapidly, and by the time Chicago’s understaffed fire department could respond, it had engulfed numerous nearby buildings. Initially, it was hoped that a portion of the Chicago River would act as a barrier against the fire’s further spread. However, the intense heat and strong winds allowed the fire to jump the river and spread to the city’s center.

The fire’s intensity was such that it generated tornado-like winds that further accelerated its spread. Firefighters continued to combat the fire until the water works, which were located nearby, caught fire and burned down. This setback rendered the firefighters unable to effectively control the fire, and they were left to watch as it engulfed the city’s outskirts until it reached the city’s edges and began to rain. By that point, there was minimal material left to burn.

Upon the fires’ eventual peterout and the safety of the area, it became evident that the devastation caused by the fire was extensive. An area spanning 4 miles in length and 3/4 miles in width was completely destroyed. 73 miles of road and 17,500 buildings were obliterated. Approximately 100,000 people, which represented about 1/3 of the city’s total population, became homeless.

After the fire, 120 bodies were discovered, although the death toll may have reached as high as 300. The total value of the property loss amounted to $222 million, which is equivalent to over $4 billion in today’s currency. Despite the immense challenges, international aid poured into Chicago, enabling the city to rebuild and recover from the devastating fire.