Today in History: The Great Chicago Fire Broke Out

“On Oct. 8, 1871, the Great Chicago Fire erupted; over 300 people died and over 17,000 structures were destroyed during the three-day blaze,” with roughly 3.3 square miles (or 9 square kilometers) destroyed and approximately 100,000 left homeless. Chicago Cop has a detailed article about the fire, including it cause, of which he writes:

    On October 8, 1871 at about 9:00 p.m. in or around a small barn belonging to Patrick and Catherine O’Leary a fire began. The barn bordered the alley behind No. 137 DeKoven Street (present day 558 West DeKoven Street) and a shed next to the barn was the first structure to be consumed by the fire. The fire quickly spread, but the real cause has never been determined by city officials. Over the years there have been several claims about how the blaze began. The most common tale blames Mrs. O’Leary’s cow, who is said to have knocked over a lantern in the barn. Other claims state that a group of men were gambling inside the barn and knocked over a lantern. Another claim alleges the blaze was related to other fires in the Midwest that day.

    The predominant method of building structures was called balloon framing which relied heavily on wood for the building material. More than two thirds of the structures in Chicago at the time were constructed using this method.  In addition to the wood, the roofing materials used, such as tar or wood shingles, were highly flammable.  Add in the fact that the city’s sidewalks and most roads were constructed from wood this created a recipe for disaster. Prior to the fire Chicago had received only 1 inch of rain from July 4 to October 9. This caused severe drought conditions and with the strong southwest winds, to help carry flying embers, the fire quickly spread into the heart of the city.

The spread of the fire was aided by the fact that Chicago was in the midst of a long drought, there had been numerous other fires that summer, and the scanty number of firefighters and steam engines were initially sent to the wrong location. 

    Chicago Cop adds (footnotes omitted):

When firefighters finally arrived at the O’Leary barn, the fire had spread to neighboring buildings and was rapidly progressing towards the central business district. Firefighters had hoped that an area of land which had previously burned and the South Branch of the Chicago River would act as a natural firebreak. However, lumber yards, warehouses and coal yards in addition to barges and numerous bridges lined the river and helped the fire jump its banks. As the fire grew, the southwest wind intensified and became super heated, causing structures to catch fire from the heat and from burning debris blown by the wind. Around 11:30 p.m., flaming debris blew across the river and landed on roofs and the South Side Gas Works. 

And: 

    As more buildings succumbed to the flames, a major contributing factor to the fire’s spread was a meteorological phenomenon known as a fire whirl. As overheated air rises, it comes into contact with cooler air and begins to spin creating a tornado-like effect. These fire whirls are likely what drove flaming debris so high and so far. Such debris was blown across the main branch of the Chicago River to a railroad car carrying kerosene. The fire had jumped the river a second time and was now raging across the city’s north side.

    Despite the fire spreading and growing rapidly, the city’s firefighters continued to battle the blaze. A short time after the fire jumped the river, a burning piece of timber lodged on the roof of the city’s waterworks. Within minutes, the interior of the building was engulfed in flames and the building was destroyed. With it, the city’s water mains went dry and the city was helpless. The fire burned unchecked from building to building, block to block.

 Rain put out the fire about a day later--although it was already beginning to burn itself out.

    Although the fire had destroyed most of the business district, it left the stockyards and the new packing plants on the South Side untouched as well as most of the rail road tracks. "Most of the wharfs, lumberyards, and mills along the Chicago River survived, as did two-thirds of the grain elevators to the west." Consequently, the city remained financially stable. And the largely intact railroad tracks allowed assistance to come pouring in from the rest of the nation and even from overseas. For instance, "[b]ook donations collected in England became part of Chicago's first free, public library."

    After the fire, the city mandated that new construction be made of fire proof materials such as stone and brick. Unfortunately, although many people had fire insurance before the fire, the fire had also burned their policies (a good reason to make sure important documents be kept in fireproof boxes of safes). Between the increased construction costs and lack of insurance, many people were forced to abandon Chicago. But even in the reconstruction there was innovation: "Terra-cotta clay emerged as a popular and effective building material. By the mid-1880s, terra cotta tiling made Chicago one of the most fireproof cities in the nation."