 In early March, when the Russians attacked the Germans, Jednorożec was on the front lines and, by March 1915, more than half of the village was destroyed.A Polish resistance group, called "Polish Military Organisation" (Polska Organizacja Wojskowa) was formed during the war and included a number of the village's residents, including Franciszek Berk, Stanisław Kardaś, Władysław Mordwa, Jan Sobieraj, Antoni Wilga and Józef Wilga.When, in August 1915 residents began returning to Jednorożec, which was now under German occupation until 1918, there were only three remaining buildings