France opens separate technical investigation into Cléon derailment

France has now opened a BEA-TT technical investigation into the Cléon derailment, separate from the judicial inquiry already under way at the Rouen public prosecutor’s office.

The regional train was travelling from Rouen to Caen on Friday 11 September. It left the track near Cléon, in Seine-Maritime. SNCF puts the time at about 19:30. Meanwhile, the prosecutor’s office counted 44 injured among the 186 people on board. A helicopter took an 18-year-old woman to Rouen University Hospital in a critical condition. However, the same office said the next evening that her life was no longer in danger.

The Rouen public prosecutor’s office has set out a leading hypothesis. A piece of another rail lay on one of the running rails. So far, though, nothing establishes that anyone placed it there deliberately. The office has therefore cautioned against describing the derailment as a deliberate act, still less a terrorist attack. Tests on the driver for alcohol and drugs came back negative. Investigators also seized the train’s data recorder. In addition, a court-appointed expert has since visited the site.

What the BEA-TT inquiry covers

France’s land transport accident investigation body, the Bureau d’Enquêtes sur les Accidents de Transport Terrestre, registered the Cléon case on 12 September. That came one day after the derailment. Its presentation sheet is still in preparation. Under the Transport Code, its investigators work under professional secrecy. A final report will be published when the inquiry ends, although the bureau may issue interim information notes before then.

The prosecutor’s office describes that work as a separate investigation, distinct from the judicial one. Furthermore, it says it intends to coordinate with the bureau.

Rouen–Elbeuf services remain suspended

SNCF Nomad Train reports that trains remain suspended between Rouen and Elbeuf in both directions, while services continue between Caen and Elbeuf. Yvetot–Rouen–Elbeuf trains terminate at Sotteville. The operator has published separate daily timetables for the Rouen–Caen and Elbeuf–Yvetot routes through Friday 18 September. However, it says the reopening date remains undetermined. Between Rouen and Elbeuf, passengers can use the My Astuce urban network. A single ticket costs €1.80, while passengers under 18 can obtain a free seven-day ticket.

Planned work in the Sainte-Catherine tunnel had already closed the same section to direct trains that weekend. Normal running was due to resume at 16:00 on Sunday. Instead, the derailment closure continued. SNCF says an operation to lift the train is now under way. Initial assessments indicate major damage to the track and electrical installations, and the operator expects complex repairs. Two SNCF staff were on board, and the group has opened a psychological support line for those affected.

SNCF has published daily timetables through 18 September but has not announced when normal services will resume. Source: SNCF Nomad Train, Incident ligne Caen – Rouen, accessed 14 September 2026.

Other rail investigations open in France

The Cléon case joins eight other railway inquiries on the bureau’s active list. One concerns a combined transport train that derailed at Carentan, also in Normandy, on 11 January 2026. Another covers a near head-on movement between two SNCF Voyageurs trains at Marseille in September 2025. Two more date from May 2025. They cover the start of a derailment of a TGV at Tonneins and a derailment with an incipient fire on a regional train at Laon. The oldest case, a freight derailment at Carcassonne, goes back to November 2022. It has produced three interim notes so far.

Nine railway investigations were open when the Cléon case was added, and the oldest had been running since November 2022. Source: BEA-TT, Les enquêtes en cours, page updated 12 September 2026.