There was a major train bombing/derailment in 1961 that killed 28 people and injured many more. It was perpetrated by the OAS (Organization de L'armée Secrète), a right-wing paramilitary group who were opposed to Algerian Independence (which the French public had just voted to endorse in a referendum).

This is probably not a reference to one specific attack, but to the rash of terrorist incidents associated with Algerian independence.

From about 1954 to 1962, the Algerian FLN (National Liberation Front) engaged in terrorist activity so successful that it led to the dissolution of the French government (the Fourth Republic) and the creation of a new one, with aging war hero Charles de Gaulle at the helm. On the opposing side, the "Red Hand", a state-sponsored secret counterterrorist organization, employed terrorist tactics against the revolutionaries.

After de Gaulle relinquished France's claim to Algeria, French right-wing militants of the OAS (Secret Army Organization) committed numerous acts of violence, including bombings, sabotage and assassinations, to pressure the government into backing down. In particular, they tried repeatedly to assassinate de Gaulle.

"The Algerian war of independence was one of the longest and bloodiest decolonization struggles of the 20th century. Because of the conventional superiority of the French army, the FLN relied on asymmetric guerrilla warfare and terrorist tactics. To defeat this threat, the French security forces adopted some of the methods of their enemy: ‘Like them they had to be utterly ruthless.’" ("The State as a Terrorist: France and the Red Hand." Perspectives on Terrorism 6:6, 2012.)