What Is the Deadliest Wildfire in History?

Wildfires erupt from a deadly confluence of extreme weather conditions and primed fuel sources. Drought, heat, and wind dry out timber and grasses, making them vulnerable to ignition. Once burning begins, those same environmental factors can increase a fire’s intensity and spread it over vast distances. Flash fuels—such as dried grass, leaves, and light branches—kindle readily and spread fire quickly, often generating enough heat to ignite heavier fuels such as tree stumps, heavy limbs, and the organic matter of the forest floor. Once ablaze, these fuels are difficult to extinguish, contributing to sometimes-catastrophic destruction and loss of life when residents are overtaken by fast-moving fire and smoke.

The summer and early autumn of 1871 were unusually dry in the American Midwest. The Peshtigo Fire—widely believed to have been ignited by a brush fire started by railroad workers—began in the vicinity of the logging and lumber goods manufacturing community of Peshtigo, Wisconsin, before jumping Green Bay to spread to the counties of Brown, Door, and Kewaunee, among others. The fire ultimately burned between 1.2 and 1.5 million acres and caused 1,152 verified deaths. Some estimates suggest that the death toll was much higher, but the fire destroyed town records documenting the populations of the affected towns. Additionally, many residents of remote farmsteads and camps in the wilderness were not documented at all, and their settlements—and their bodies—were burned beyond identification.

The Peshtigo Fire remains the deadliest wildfire in recorded history, yet the conflagration is little known outside of Wisconsin. The reason? The fire broke out on October 8, the same night as another blaze some 250 miles to the south—the Great Chicago Fire, one of the most famous urban fires in American history.

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The map and table below list other wildfires that share the grim distinction of being among the world’s deadliest.