Observed each year, Sunday through Saturday during the week that includes October 9th. Fire Prevention Week was established to commemorate the Great Chicago Fire of 1871. The fire began on October 8, but continued into and did most of its damage on October 9, 1871.
While the Great Chicago Fire was the best-known blaze to start during this fiery two-day stretch, it wasn't the biggest. That distinction goes to the Peshtigo Fire, the most devastating forest fire in American history. The fire, which also occurred on October 8, 1871, and roared through Northeast Wisconsin, burning down 16 towns, killing 1,152 people, and scorching 1.2 million acres before it ended.
More information on the National Fire Protection Association website.