Over the past 15 years, our research group has conducted a planned series of studies concerning children exposed to catastrophic violence and disaster. These studies have included traditional epidemiological surveys in which we examined the prevalence and course of symptom reactions in children exposed to large-scale disasters, to catastrophic community violence, or to war and occupation. For example, we have completed studies of school-age children directly exposed to a 1984 sniper attack on their school playground in South Central Los Angeles, the 1988 Spitak earthquake in Armenia, and the 1991 Iraqi invasion of Kuwait. In other studies we have obtained detailed clinical material from several cohorts of children who witnessed different forms of extreme interpersonal violence -- for example, the homicide or rape of a parent or a parent's suicide attempt. Recently, our group has collaborated in studies of young children exposed to life-threatening illness and life-endangering medical procedures. In addition to systematic assessment of clinical symptoms, these studies have included in-depth interview material that permits exploration of children's subjective experiences, microanalysis of their memory operations, and examination of developmental processes. More recently, these investigations have also included pilot examination of potential neurophysiological disturbances and their developmental implications. In addition, we are currently examining strategies of intervention, from school-based public health methods of psychological first aid to principles of brief and long-term therapy. We have been especially interested in strategies of pulsed interventions over the course of the child's further development.