With the outbreak of World War I, the proximity of the border proved disastrous for Kalisz; it was one of the first cities destroyed in 1914. Between 2 and 22 August, Kalisz was shelled and then burned to the ground by German forces under Major Hermann Preusker, even though Russian troops had retreated from the city without defending it and German troops – many of them ethnic Poles – had initially been welcomed peaceably. Eight hundred men were arrested and then several of them slaughtered, while the city was set on fire and the remaining inhabitants were expelled. Out of roughly 68,000 citizens in 1914, only 5,000 remained in Kalisz a year later. By the end of the Great War, however, much of the city centre had been more or less rebuilt and many of the former inhabitants had been allowed to return.