In the hills of eastern Pennsylvania, a fire has been burning underground for more than six decades, consuming coal deep beneath the ground where the town of Centralia once stood. Ignited in 1962, the blaze crept into a labyrinth of abandoned mine tunnels and has proved impossible to extinguish, ultimately driving out nearly everyone who lived above it. Centralia has become the country’s most infamous coal-seam fire and a lasting emblem of a hazard that can outlast generations.
How a trash fire reached the coal below
The fire’s origin is deceptively mundane. In May 1962, the borough set out to clean up its landfill ahead of a Memorial Day holiday, and the chosen method was to burn the refuse in an abandoned strip-mine pit. According to state resources on the mine fire, the fire found its way into the underground coal workings, and once it reached the coal seams it became self-sustaining, feeding on a fuel supply vast enough to burn for a very long time.
Investigators have pointed to an unsealed opening into the old mine as the likely pathway that let the surface fire descend into the tunnels. What began as an effort to tidy a dump instead lit a fuel source that no one could easily put out.
Why decades of effort could not stop it
Extinguishing a coal-seam fire is extraordinarily difficult because the flames burn out of reach, deep within the earth and constantly supplied with fresh coal. According to a detailed account of the disaster, state and federal authorities spent years and considerable sums attempting to halt the Centralia fire through excavation, flushing, and other methods, none of which succeeded in stopping its underground advance. The fire simply followed the coal, spreading through the seams faster than crews could contain it.
Firefighting techniques that work on surface blazes are largely useless against a fire that is insulated by hundreds of feet of rock and soil. Cutting off its oxygen or fuel would require excavating an enormous volume of ground, a task that repeatedly proved impractical at Centralia.
The scale of the underground burn
The fire is far larger than the small town it displaced. According to documentation of the fire, it has been burning through the Buck Mountain coal bed at depths reaching up to about 300 feet, spreading along an eight-mile stretch and affecting an area on the order of 3,700 acres. Coal-seam fires occur in many places, but Centralia’s is regarded as one of the most destructive in the country’s history.
Its effects surface in visible and hazardous ways: ground that grows warm to the touch, plumes of steam and smoke rising from fissures, and pockets of dangerous gases such as carbon monoxide seeping upward. Sinkholes can open without warning where the fire has hollowed out the ground beneath.
How a coal-seam fire sustains itself underground
What makes a fire like Centralia’s so intractable is the nature of its fuel and its setting. Coal is an energy-dense fuel packed into seams that can run for miles, and once ignited it can smolder slowly, consuming the seam a little at a time while drawing oxygen through the porous, fractured ground and old mine passages around it. The fire does not need a dramatic blaze to persist; a steady, low-temperature burn deep underground can continue almost indefinitely as long as coal and air remain available.
That combination places the flames beyond the reach of conventional firefighting. Water poured from the surface struggles to penetrate to a fire burning hundreds of feet down, and starving it of oxygen would require sealing off an enormous, irregular network of underground voids. The most reliable way to stop such a fire is to excavate or isolate the burning coal entirely, an undertaking that at Centralia would have meant digging out a huge volume of earth at prohibitive cost. Each attempt over the years ran up against that fundamental obstacle.
The surface signs of the fire below
Though the fire burns out of sight, its presence is unmistakable at ground level. In affected areas the earth can feel warm underfoot, and steam and smoke rise from cracks in the ground, particularly in cold weather when the contrast is starkest. Vegetation dies where the soil grows too hot, leaving scorched patches, and the burning coal releases gases, including carbon monoxide and carbon dioxide, that can accumulate to dangerous levels in low-lying or enclosed spaces.
Perhaps the most alarming hazard is subsidence. As the fire consumes coal, it hollows out the ground and undermines the surface above, which can give way suddenly to form sinkholes. A widely recounted episode from the early 1980s, in which a young resident narrowly escaped after the ground opened beneath him and vented hot, toxic gases, helped crystallize public alarm and accelerated the push to relocate the town. These visible and invisible dangers, warm ground, noxious gases, and unstable earth, are what ultimately made continued life in Centralia untenable.
A town emptied by the fire beneath it
The human cost of the fire unfolded gradually. As toxic gases, subsidence, and the ever-present risk of collapse made the town unsafe, authorities moved to relocate residents. In the 1980s, government programs bought out and cleared most of Centralia’s buildings, the population dwindled to a handful of holdouts, and the borough’s ZIP code was eventually revoked, formally erasing it from the postal map.
Today Centralia stands as a near-ghost town, its street grid still faintly visible amid reclaimed land, with smoke still rising in places as the fire continues its slow work below. Estimates suggest the underground blaze has enough coal to keep burning for many more decades, a reminder that some fires, once started in the right conditions, can outlast the communities that unwittingly set them.
This article was produced with the assistance of AI and reviewed by Morning Overview editors prior to publication.
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