A newly published expert report on the 2023 Tempi train disaster, which tragically claimed 57 lives, has cast doubt on earlier theories suggesting the explosion and massive fireball following the collision were caused by an unknown flammable substance. Instead, the report concludes that engine oils—particularly silicone oils—were likely responsible.
The 123-page report, commissioned by the appellate examining judge and authored by Professor Dimitris Karonis of the National Technical University of Athens, contradicts previous findings from the Hellenic Aviation and Railway Safety Investigation Agency (HARSIA). That earlier report, published in February, supported claims from the opposition that the explosion may have been caused by an unidentified liquid carried by the freight train.
Karonis’s findings are grounded in a broad analysis that included data from the General State Chemical Laboratory, site inspections, material samples, and international scientific comparisons. The report concludes that silicone oils—ignitable at temperatures above 330°C—could have caused the explosion under the intense conditions created by the crash, particularly due to high-current electric arcs that were reportedly observed at the time of impact.
“The formation of a fireball under conditions of high-current electric arc is possible,” Karonis notes, emphasizing that such flashes were recorded in the aftermath of the collision.
In a parallel investigation, a second expert report by NTUA professor Petros Tsakiridis examined the wreckage of the freight train at the Koulouri site. It found no evidence of burning or explosion in the locomotive cockpit or frame, noting only physical deformations consistent with the force of the impact.
Government spokesperson Pavlos Marinakis welcomed the new findings, criticizing what he described as a politically driven effort to manipulate public opinion. “Today puts an end to the most obscene effort to manipulate public opinion that I can remember,” he said. “The narrative of a cover-up comes crashing down. If there was no illegal cargo, then what was there to hide?”
Marinakis added that the earlier HARSIA report merely presented the existence of an unknown fuel as a possibility, not a confirmed fact, and that hypothesis had already been challenged by academic institutions at the time.
The findings aim to provide clarity in a case that has deeply shaken Greek society and sparked intense political debate. Earlier this year, massive demonstrations took place in Athens and other Greek cities demanding justice for the victims of Tempi. The conservative government survived a vote of no confidence tabled by most opposition parties in March.
The official investigation into the causes and accountability for the disaster continues.
Related: Tempi Greek Tragedy: From Mass Protests to Political Showdown
