What are the long-term socioeconomic impacts of wartime violence? We use historical aerial imagery of the aftermath of the United States’ indiscriminate firebombing of Tokyo in 1945 to generate detailed neighborhood-level data on damages—helping us to overcome the methodological challenges of nonrandom assignment and coarse measurement. Decades after the air raids, the most heavily damaged neighborhoods continued to suffer socioeconomically—with higher crime, lower educational attainment, and higher unemployment. Causal mediation analysis reveals that these patterns cannot be explained by the ratio of new residents or the construction of high-rise buildings, and a geo-coded survey featuring behavioral experiments indicates less altruism in affected neighborhoods. In contrast to previous studies that stress how violence might affect social cohesion (positively or negatively) through individual or family-level trauma, our findings suggest that community-level exposure to violence might create persistent legacies by displacing victims and altering the urban landscape, thereby fragmenting local communities.