ON AUGUST 2, 1980, A neo-fascist terrorist group hid a time bomb at the BolognaBologna Centrale station, killing 85 people and wounding more than 200. It is one of the major incidents during the tumultuous Years of Lead, the period of social and political strife that lasted from the 1960s to the 1980s,  and arguably the very worst of these.

Some time after this massacre, a subtle controversy occurred concerning the station’s clock. In a 2010 study, local people were asked about it, and 92 percent of them responded that they remembered the clock had stopped since the bombing. But, as it turned out, this was a collective false memory, a phenomenon commonly referred to today as the “Mandela effect.”