According to Gibrat’s law for cities, population shocks have permanent effects on city size. I examine this implication by analysing the persistence of observed population shocks: German military casualties in WWI by municipality of birth. I find a strong negative effect of military casualties on the male population of municipalities just after WWI. This effect persists to 1933 and, outside of the most agricultural municipalities, beyond. The effect on female population and the number of households is similar to the effect on male population by 1950, when women in the generation that fought WWI started reaching their life expectancy.