In 1999, in Denver, CO, 2 youths attacked Columbine High School and killed 12 classmates, 1 teacher, and injured more than 20 others before taking their own lives. This attack far exceeded the magnitude of previous school violence and has become known as America’s deadliest school assault. In addition to the shooting victims, many were traumatized through witnessing killings, seeing killed or injured peers, as well as seeing and hearing indications of the attack. This report provides qualitative information from individuals interviewed in the immediate aftermath of the attack on Columbine High School. The intent was to document the experiences and reactions of some victims and allow for more informed study of responses to such events. The intent was also to glean from the adolescents and their parents’ insight into immediate psychological effects of their experiences with mass violence focusing on understanding emotional and cognitive responses, feelings about talking to others about their experiences, and the larger context of general social responses. Four female Columbine High School students ages 15 to 17 and seven parents (six female) ages 41 to 49 were interviewed. A significant finding from the study is that there exists important variation in responses during the earliest period after a traumatic event. Emotional reactions were quite variable during the first 2 weeks after the trauma. Negative emotions were not uniformly more prominent than positive ones with the most intense emotion reported being affection. Lastly, the importance of making sense of the event varied notably between individuals, and the desire and ability to do this was not uniform. References