Objective The definition of psychological trauma, which was traditionally restricted to immediate and direct experience, is now expanding to include mediated or vicarious experience. So the present study aims to examine the relationship between the negative effects and the positive outcomes to a national disaster by assessing the posttraumatic stress disorder (PTSD) symptoms and posttraumatic growth of the general public. Methods A nationwide survey of the Korean population (n=811) who were exposed to the Sewol ferry disaster through the media participated in this research, completing a self-report questionnaire consisting of demographic characteristics, Impact of Event Scale-Revised-Korean, and Korean-Stress-related Growth Scale-Revised. The participants were divided into three groups according to the severity of PTSD symptoms, then one-way ANOVA were conducted. Results The results revealed 30.4% of the sampled participants reported stress symptoms equivalent to partial or full PTSD. Posttraumatic growth was significantly higher in the full and the partial PTSD symptom groups when compared to the normal group [F (2,759)=20.534, p<0.001]. At a subscale level, mature thinking showed a more significant result [F (2,759)=23.146, p<0.001] than religious growth [F (2, 180.984)=4.811, p<0.01]. Conclusion The results indicated a general linear trend between the severity of PTSD symptoms and posttraumatic growth level, suggesting that indirect trauma also induces both PTSD symptoms and posttraumatic growth like direct trauma does. The theoretical implications based on these findings were discussed.