French police are investigating the possibility of sabotage after a train derailment in Normandy left 44 people injured, including one in critical condition, on Friday evening.

The train, carrying 186 passengers, went off the rails around 7:45 p.m. local time between Rouen and Caen. One carriage overturned completely, and four others derailed after the train struck a "massive section of rail" on the track. Investigators found the fragment, weighing between 250 and 300 kilograms, at the scene.

"The reasons for its presence are unknown and will have to be determined by the investigation," said Prosecutor Sebastien Gallois. Authorities activated a mass-casualty response plan, deploying 130 firefighters, five medical teams, and 80 vehicles to the site.

Herve Morin, president of the Normandy region, stated that the incident was likely not a simple accident. "The section of rail did not just end up on the tracks like that, given that a train had passed an hour earlier and no maintenance work had been carried out in the meantime," he said.

An 18-year-old female passenger was airlifted to Rouen University Hospital in critical condition, but her status was later updated to no longer critical, though she remained hospitalized. Other passengers were taken to Cleon Town Hall. Cleon's mayor, Melanie Delacour, described the victims as being "in a state of shock," adding that some had expressed they would never travel by train again.

Investigators remained at the scene on Saturday as police focused on the possibility of a criminal act. The train's driver tested negative for alcohol and drugs. The maximum speed on that stretch of track was 120 kilometers per hour.

SNCF Reseau, the French rail network infrastructure manager, reported that rail traffic was initially suspended. Services have since resumed, but the train will only be removed from the line after the public prosecutor grants permission. SNCF stated it would cooperate fully with the inquiry.

A large fragment of rail near the site of the derailment, which injured 44 passengers on Friday night