This study investigates the impact of primary-school closures during the 1918 Pandemic in Sweden on mortality and the long-run outcomes of children. Combining the universe of death certificates for over 500,000 individuals from 1914 to 1920 with newly-collected archival data on school closures in more than 2,100 school districts, we employ high-frequency event studies at both weekly and daily intervals to examine the relationship between mortality and school closures. Our findings show that schools were closed in response to a local surge in influenza-related deaths two weeks prior to the closure. Next, we exploit the speed of closure and document that implementing school closures faster significantly reduced peak-level mortality rates, effectively saving the lives of primary-aged individuals. Finally, we track the long-term outcomes of the affected school children (around 100,000 per school grade) throughout their life cycle and compare them to those who were too young to attend school during the pandemic school closures. The precise estimates reveal relatively minor and mostly inconsequential effects of the closures on various outcomes, including longevity, employment, and income.