Editing Great Chicago Fire (section)

==Spread==
[[File:Great Chicago Fire map with starting point cropped with arrow.jpg|thumb|477x477px|1869 map of Chicago, altered to show the area destroyed by the fire (location of O'Leary's barn indicated by red dot and arrow)]]
When firefighters finally arrived at DeKoven Street, the fire had grown and spread to neighboring buildings and was progressing toward the central business district. Firefighters had hoped that the South Branch of the Chicago River and an area that had previously thoroughly burned would act as a natural [[firebreak]].<ref name="DonaldMiller"/>{{rp|147}} All along the river, however, were lumber yards, warehouses, and coal yards, as well as barges, and numerous bridges across the river. As the fire grew, the southwest wind intensified and the temperature rose, causing structures to catch fire from the heat and from burning debris blown by the wind. Around midnight, flaming debris blew across the river and landed on roofs and the South Side Gas Works.<ref name="DonaldMiller"/>{{rp|148}}

With the fire across the river and moving rapidly toward the heart of the city, panic set in. About this time, Mayor [[Roswell B. Mason]] sent messages to nearby towns asking for help. When the courthouse caught fire, he ordered the building to be evacuated and the prisoners jailed in the basement to be released. At 2:30&nbsp;a.m. on the 9th, the cupola of the courthouse collapsed, sending the great bell crashing down.<ref name="DonaldMiller"/>{{rp|148}} Some witnesses reported hearing the sound from a mile (1.6&nbsp;km) away.<ref name="DonaldMiller"/>{{rp|150}}

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]].<ref>{{cite web |last=Abbott |first=Karen |title=What (or Who) Caused the Great Chicago Fire? |url=http://www.smithsonianmag.com/history/what-or-who-caused-the-great-chicago-fire-61481977/ |date=October 4, 2012 |work=Smithsonian Magazine |access-date=February 24, 2014}}</ref> As hot 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]].<ref name="DonaldMiller"/>{{rp|152}} 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.<ref name="DonaldMiller"/>{{rp|152–3}} The fire burned unchecked from building to building, block to block.{{citation needed|date=October 2019}}

Late in the evening of October 9, it started to rain, but the fire had already started to burn itself out. The fire had spread to the sparsely populated areas of the north side, having thoroughly consumed the densely populated areas.<ref name="DonaldMiller"/>{{rp|158}}