In the Franco-Prussian War, Karfunkelstein distinguished himself so conspicuously that on 28 October 1870, he was decorated with the Iron Cross, second class. Two days later he was mortally wounded during field of battle at Le Bourget on 30 October when he stormed the first barricade, while rescuing the regimental flag from the hands of the enemy. He was, however, able to hand it to General Budrisky. According to some accounts, Karfunkelstein had jumped out to grab the flag and was shot through the chest, the bullet grazing the iron cross that he was wearing around his neck.