The drama took place at 4:59 a.m. on Tuesday, 700 m from Saint-Jean-de-Luz station.
Three migrants of Algerian nationality lost their lives, hit by a train.
A fourth victim, also Algerian, is seriously injured.
All three died instantly, the fourth individual was rescued by the conductor and two controllers who were on board the train.
The public security police officers arrived five minutes later at the scene of the tragedy, one of them was able to practice a tourniquet on the surviving victim whose vital prognosis was then engaged.
The victims were "lying on the tracks without anyone knowing why" announces Eric Marrocq, regional secretary of the Alliance union.
"The driver told me that the individuals were lying on the rails and were not moving, it was dark, he saw them at the last moment", adds the station master, shocked by the news.
The TER had left Hendaye station thirteen minutes before the collision.
"He was traveling at 92 km / h, in an unlit area difficult to access by road," said Jérôme Bourrier, the Bayonne prosecutor, during his press conference on Tuesday.
"This drama highlights the significant migratory flow, with the arrival of migrants in Spain, the gateway to Europe and whose Basque coast has become a strategic crossing point" explains Eric Marrocq.
