Numerous researchers discuss the solidarity-producing effects of crime, natural disasters and mass tragedies; however, there is much we do not understand about the processes involved in the phenomena. We specify the social relationships that "generate" and "sustain" solidarity by building on Hunter's descriptions of the private, parochial and public spheres of community. We argue that event-specific parochial and event-specific public activities "generate" solidarity after heinous crimes. However, general parochial activities, such as attending local organizational meetings and frequenting local businesses, "sustain" solidarity. Using longitudinal data collected after the mass murder of 27 students and 5 faculty members on Virginia Tech's campus in 2007, a repeated measures analysis predicting levels of solidarity 5, 9 and 13 months after the tragedy supports our hypotheses. (Contains 2 tables, 1 figure, and 4 notes.)