Greece's Fire Service has traced the cause of a destructive wildfire that swept through Boeotia and Attica to a short circuit produced by the swaying of two power transmission cables, according to the findings of an investigation carried out by officers from the Fire Service's Directorate for Arson Crime Investigation.
According to sources, in the site inspection report drawn up for the case, investigators state that, based on the preliminary material gathered, the sole cause of the fire appears to be sparks generated by an electric arc from power distribution cables belonging to a private network running from the wind farm at the Mavro Spithari site.
The sparks were thrown into dry grass in the direction of the wind, from north to south, over a distance that could exceed 10 meters because of strong north winds reaching 7 on the Beaufort scale, with gusts of 11 to 12 Beaufort.
What the site inspection found
The inspection carried out at the point where the fire began established several findings, according to investigators.
- No remains of known incendiary devices were found.
- No evidence emerged that an unknown person had approached the fire site, which is especially hard to reach on foot, without being noticed, to set a fire with an open flame.
- No hot works were found to have taken place near the original ignition point.
- No materials were found capable of causing a fire through self-ignition or refraction.
- No traces of smoking materials were found.
- No visible signs of gunfire on the private overhead network were found.
The inspection also established that a private medium-voltage electricity distribution network runs through the area. Part of it runs underground before becoming an overhead line on wooden poles, following the terrain and ending at the wind farm installation on the neighboring ridge, where the turbines are located.
At the spot where the fire broke out, investigators found a wooden pole from the overhead medium-voltage distribution line down on the ground, with the network's cables also fallen within the burned area.
Sections of cable from the overhead distribution network that had fallen to the ground showed local deformation and thermal damage to their metal strands, the inspection found.
Investigators said this damage was not the result of the fire itself but a pre-existing condition that predated the fire, pointing to the generation of sparks that were then carried into the dry grass in the direction of the wind, from north to south, over a distance that could exceed 10 meters given the strong north winds.
The site inspection report stated that the fire burned at least 130,000 stremmas (a unit of land measurement in Greece) of forest land, along with areas of low vegetation, farmland and homes.
A fire that struck the same line a month earlier
Investigators attached particular significance to the fact that on June 27, 2026, at 11:14 a.m., a fire had broken out on the same distribution line, about 150 meters from the site where the July 31 fire began.
According to a case file compiled by the Thebes Fire Service, that earlier fire was attributed to a short circuit caused by contact between two of the line's cables, which produced sparks that were thrown into dry grass. The cables involved were seized as evidence.
Investigators said the earlier incident showed that the same line had already suffered a similar failure, which they described as a serious indication of recurring problems in the network's operation or condition.
The cause investigators identified
Based on the preliminary material they gathered, investigators concluded that the sole cause of the fire was the generation of sparks from an electric arc in the power distribution cables of the private network running from the wind farm at Mavro Spithari, which were thrown into dry grass in the direction of the wind, from north to south, over a distance that could exceed 10 meters because of the strong north winds of 7 Beaufort, with gusts of 11 to 12 Beaufort.
Two people have been arrested in connection with the case: the electrical engineer who supervised the network and the contractor responsible for the project.
