Japanese society's notion of safety shaken to its core

A traffic-free street packed with shoppers and pedestrians on an early Sunday afternoon transformed rapidly into a disaster zone.

A 25-year-old male temporary worker ploughed a truck into a crowd before slashing one person after another with a double-edged survival knife. This indiscriminate stabbing frenzy in Tokyo's electronics shopping district of Akihabara left seven people dead and 10 injured.

Among the victims were two male university students who went to Akihabara with two other friends to see a movie, and a former dentist who visited the district with his eldest son to buy personal computer-related items. Who, including the families of the victims, would have predicted that such an attack would occur?