Objective: Guided by conservation of resources theory, this study provides empirical data on students’ psychosocial adjustment following a mass murder tragedy, what changed or did not change from their pretragedy adjustment levels, and their view on what helped most in the immediate aftermath. Method: Students (n = 593) who participated in a study of college adjustment the year prior to a mass murder that affected the university community were recontacted following the tragedy, providing prospective, longitudinal data (n = 141 pretragedy Time 1 and posttragedy; n = 73 pretragedy Times 1 and 2 and posttragedy). Results: For both anxiety and depression, repeated-measures analysis of variance showed a significant Time × Resource Loss interaction. Students with any resource loss had a steeper incline in symptoms than did students reporting no resource loss. From pre- to posttragedy, there was an increase in psychological sense of school membership but no change in general self-efficacy and social support. Students with clinical levels of posttragedy distress reported more childhood trauma and depression symptoms at college entry. Student-initiated and -led memorial activities were rated as most helpful. Implications: Perceived resource loss is important in understanding the impact of the trauma on mental health and could be a part of intake for supportive services. Given that it was the students with greater prior trauma exposure and depression symptoms who were more likely to have clinical distress posttragedy, targeted outreach to current and former university counseling center clients to “check in” may be helpful to reach those who may be in most need.