KG 55 was also heavily involved in the Battle of the Bzura. Three Polish Army groups attempted to break out of an encirclement and the German Eighth Army could not contain the attack. The "Luftwaffe" initiated a large air offensive against the Polish forces on 8 September. I. and II./KG 55 were involved in attacking communication targets while other units offered close air support. The offensive was successful and the Polish resistance broken. Operations moved south thereafter, operations against bridges on the Vistula and attacks against Polish forces retreating towards Romania also absorbed much of the wing's effort. The "Geschwader" suffered its first loss when one bomber made a forced-landing with no casualties on 11 September during long-range operations against Przemysl. The "Luftwaffe" was flying further to the east by this stage.