Here’s what you’ll learn when you read this story:

• The Peshtigo Fire, which burned across northeastern Wisconsin from October 8-10, 1871, killed thousands, but few remember the blaze, as the Great Chicago Fire occurred during those same days.
• While the Chicago Fire killed hundreds and left nearly 100,000 homeless, the death toll of the Peshtigo Fire, which destroyed 12 separate communities, made it the deadliest fire in U.S. history.
• While few remember the fire’s name, the devastation inspired better logging practices and was a key catalyst in the creation of the U.S. Forest Service.

A depiction of the town of Peshtigo, Wisconsin, dated September 1871, looks like your typical bird’s-eye-illustrations popular in the 19th century—an aerial view of the quaint, midwestern village. The 136-mile Peshtigo River cuts through the town’s heart as its waters race toward Green Bay, Wisconsin. Homes, farms, and wide avenues sit nestled within a sprawling forest and a small bridge crosses the width of the nearby river.

Within a month, this town would be nothing but cinders.

You’d be forgiven for not recognizing the name, as the town of Peshtigo—and its devastating eponymous wildfire—doesn’t feature prominently in history books, and that’s because on the very same day, another national tragedy grabbed headlines: the Great Chicago Fire of 1871. While the Chicago Fire was certainly tragic—killing 300, destroying 17,000 buildings, and leaving at least 100,000 people homeless—the little-known Peshtigo Fire, which happened just a few hours north of Chicago, spread across 1,875 square miles, destroyed 12 separate communities, and killed between 1,200 and 2,500 people. Even today, in an era of increasingly warm summers and ever drier conditions due to climate change, the Peshtigo Fire remains the deadliest blaze in U.S. history.

For weeks, smoke filled the sky in the area surrounding the village, providing evidence that the massive fire had spread in every direction. But before all that, on October 8, 1871, the town awoke as usual. According to a Green Bay Press-Gazette story republished by the National Weather Service, survivor accounts claimed that railroad workers clearing land to lay tracks ended up starting a brush fire. Some other elements pitched in to build the brush fire into a sprawling blaze—that afternoon, a light breeze transformed into a full-on gale, and soon ashes started falling to the ground as a dull, red glow grew on the horizon.

“Then came a low, rumbling noise, like the distant approach of a train,” an article in the Peshtigo Times, published decades later with eyewitness accounts, reported. “The noise increased to a heavy roar, variously described as the noise of thunder or a mighty wind, and the startled people rushed into the street.”

Those who could escape made their way to the river, only to hopelessly watch their as their lives and livelihoods were consumed by the passing inferno.

As is the case with most extreme catastrophes, there’s no one single culprit for the fires that swept across the Midwest in the fall of 1871. According to the U.S. National Weather Service (NWS), a prolonged drought coupled with extremely strong winds certainly didn’t help.

“A large upper-level ridge was present across the region from July through September which would have set the stage for warm and potentially dry weather,” the NWS reported.

But Peshtigo’s relationship with its surrounding heavily forested area proved to be its downfall. With towering trees as far as the eye could see and its close proximity to Chicago, Peshtigo was a booming lumber town. In the mid-to-late 19th century, loggers frequently stripped the land without any regard for fire hazards left along the way. According to History.com, one particular issue was the large refuse piles left behind, which served as perfect tinder to feed the fires.

The blaze raged across the region from October 8 until October 10, and when it was all over, some 500 to 800 people had died in Peshtigo alone—a town with fewer than 2,000 or so residents at the time. With many of the remains charred beyond recognition, most were interred in a mass grave.

The Peshtigo fire is still studied by forest managers and firefighters and the devastation helped improve logging conditions to prevent future blazes. A perfect example of the dangers of unregulated logging throughout the country, the fires also inspired a cadre of conservationists to lobby the U.S. government for the creation of national forests throughout the U.S., eventually leading to the establishment of the U.S. Forest Service in 1905.