The derailment has moved into a potential criminal inquiry after prosecutors said a fragment of rail was recovered from the track, prompting investigators to examine whether the crash was the result of a malicious act. Rouen prosecutor Sébastien Gallois confirmed on Saturday that the piece had been found and said the reasons for its presence were "unknown".
The incident occurred on Friday evening on the service between Rouen and Caen in Normandy, shortly before 20:00 (18:00 GMT), near Cléon. Local reports put the number of people on board at 186. Emergency services treated forty-four passengers for injuries, and an 18-year-old woman was airlifted to hospital in a critical condition.
Authorities deployed around 140 firefighters and other rescue personnel to the scene. The Rouen prosecutor's office said the train driver tested negative for drugs and alcohol.
A passenger identified as Louis described the carriage jolting violently after the initial movement. He told ICI Normandie radio, "Suddenly there were a few jolts, and then after about three seconds it got stronger and stronger," adding that the windows partially shattered and stones from the track entered the carriage. "It was really shocking. I'm still shaking," he said.
Officials have not publicly confirmed media suggestions that the derailment was sabotage, and investigators are continuing to establish how the rail fragment came to be on the line. The recovery of that piece has shifted the response from immediate rescue and medical care toward a forensic and judicial phase, as investigators seek to determine whether criminal activity played a role in the crash.
The inquiry is at an early stage, with prosecutor Gallois and local teams continuing on-site examinations and evidence collection. Authorities have not disclosed further findings, and it is not yet clear what investigative steps will follow or how long the probe will take.
