Hautes Fagnes Fire: Investigation Points to Forestry Machine as Likely Origin

An investigative report by Belgian public broadcaster RTBF has pinpointed the precise origin of the devastating Hautes Fagnes wildfire—the largest ever recorded in Belgium—and identified a forestry machine conducting mowing work as the likely cause. The investigation reveals that no mowing ban was in effect in Liège province at the time, despite extreme drought conditions and explicit fire risk warnings.

The fire, which broke out on August 14, 2026, ultimately consumed approximately 3,366 hectares (8,318 acres) of the protected high moorland plateau in eastern Belgium, an area roughly the size of the city of Verviers. The blaze forced evacuations in several communities, mobilized international firefighting resources, and devastated a unique Natura 2000 protected ecosystem.

Pinpointing the Origin

Using satellite imagery from the Copernicus Sentinel-2 satellite, amateur video captured by skydivers, and drone footage, RTBF’s investigation team identified the exact point where the fire began: a rectangular plot approximately 300 meters west of the Croix Mockel, along a path called Allée du Grand Fossé, within a Natura 2000 protected zone.

Skydiving instructor Pierre Chouak, who filmed the fire’s early moments from the air, described what he saw: “We weren’t that high yet, so we could still see clearly. We really see the start of the fire, which isn’t very big yet, but we can already see the smoke plume, which is already quite significant. We didn’t see any walkers along the path, I didn’t see any vehicle there, no one.”

According to his flight schedule, Chouak places the fire’s ignition in the early afternoon. The first reports of the blaze came shortly after, and satellite imagery from that period shows a yellow point at the origin location.

Mowing Activity in the Crosshairs

Satellite images show that mowing and clearing work was carried out on the parcel between August 10 and August 14. The plot belongs to the Direction de Malmedy of the Département de la Nature et des Forêts (DNF), the Walloon public body responsible for forest management.

Nicolas Yernaux, spokesperson for the Service public de Wallonie (SPW), confirmed that mowing work was underway at the identified location. “Mowing is a technique carried out by the DNF for many years on the Hautes-Fagnes plateau to restore biodiversity,” he said. “It will indeed be up to the investigation to determine whether this hypothesis of the agricultural machine is confirmed or disproven, but there was indeed an agricultural machine working at that location.”

The Parquet of Liège has opened a judicial investigation for involuntary arson. According to initial findings, the fire’s origin could be linked to the activities of a gyrobroyeur—a flail mower attached to a tractor—that was mowing the parcel. The machine was no longer on site when the fire started.

The mowing work, previously carried out by the DNF itself, has been subcontracted to private companies for the past two years. RTBF identified and contacted the company responsible for the mowing on the day of the fire; it declined to comment. As 7sur7 reported, the company was mandated by the Walloon Region.

How a Mowing Machine Can Start a Fire

Jean-Luc Evrard, director general of a company that sells and repairs the mowing machines used in the Fagnes, explained how these machines operate. “These are mobile hammers on a rotor. They’re cutting. It’s a grinder that turns at about 2000 revolutions per minute,” he said. “So they’re in contact with wood, earth, stones. It’s true that with this kind of machine, when working at night for example, you can see small sparks, small orange spots appear if there’s contact with a stone.”

Evrard was blunt about the decision to use such equipment under the prevailing conditions: “It’s scandalous to have commissioned a contractor with such a machine in well-known drought conditions. Activity with mechanized machines on such dry sites was not at all recommended.”

No Mowing Ban in Liège Province

The investigation highlights a significant regulatory gap. While the province of Luxembourg had issued a circular prohibiting mowing work until August 14, no such explicit ban was imposed in the province of Liège, where the Hautes Fagnes are located.

The Celex (Cellule d’expertise), which monitors fire risk in natural areas, had issued a warning on August 10 stating that fire risk in open environments was “high” until August 15. The province of Luxembourg’s circular explicitly prohibited mowing work, but Liège province did not follow suit.

Governor of Liège province Hervé Jamar defended his actions, citing a police order published on July 2 and valid until September 6. “We took a clear and firm order regarding risks and fires for the entire province of Liège,” he said. “I don’t see what more I could have done. Look, I’m not going to ban a combine harvester from operating.”

Expert Assessment: Conditions Were Favorable for Fire

David Roussel, a forest technician from the French National Forestry Office (ONF) specializing in forest fire defense, was dispatched to Belgium via the EU civil protection mechanism. He assessed the conditions on August 14 as highly conducive to accidental fire outbreaks.

“We have ambient drought, vegetation drought, litter drought, soil drought, temperature, wind, humidity, which is a very important factor,” Roussel said. “And indeed, on that day of August 14, we had a number of indicators showing that the situation was favorable to accidental fire outbreaks.”

Political Fallout and Questions of Responsibility

Walloon Minister-President Adrien Dolimont, appearing before a special parliamentary commission, acknowledged the legitimacy of questions about the mowing operations. “Before condemning this view, we must first validate it,” he said, according to RTBF’s coverage. “I can’t say if that’s the origin of the fire. On the other hand, we will have to be very firm about everyone’s responsibilities.” He added: “The question is legitimate. It was perhaps not the most intelligent thing to do that day.”

Belgian Interior Minister Bernard Quintin was equally firm: “Once the investigation has determined what the responsibilities are, those who bear those responsibilities will have to take them.”

Environmental Devastation

The fire’s impact on the Hautes Fagnes ecosystem has been severe. The blaze affected a Natura 2000 protected area, including active raised peat bogs—a unique ecosystem in Belgium. The fire threatened the black grouse (tétras lyre) population: of 13 GPS-tracked individuals, only 7 could be located, with 6 near the fire origin unaccounted for. One male was rescued alive by firefighters.

Smoke from the fire caused record particulate matter pollution in Wallonia, with nearly 800 micrograms of fine particles per cubic meter measured in areas southwest of the Hautes Fagnes plateau.

Investigation Continues

Two experts have been appointed—one specialized in fire investigation and one in vehicle and rolling mechanics. The parquet stated that several months will be needed before their final reports are submitted. As the DH reported, the investigation is expected to be a long process.

The Walloon Region plans to request assistance from the EU Solidarity Fund, and authorities are developing a climate adaptation strategy in response to the disaster. The official Wallonie.be page continues to provide updates on the situation, including road closures and safety measures.

As the investigation unfolds, the central question remains: could this devastating fire have been prevented? With the evidence pointing to mowing activity in known drought conditions, and with a neighboring province having explicitly banned such work, the answer may have significant implications for how Belgium manages its natural areas in an era of increasing climate risk.