On 16 July, Konev took a great risk and committed Lieutenant General Pavel Rybalko's 3rd Guards Tank Army to the southern assault. This meant that the Army would have to travel through the narrow "Koltiv Corridor", constantly under artillery fire and fierce German counterattacks. The 3rd Guards Tank tilted the balance in the Lviv direction, and soon the Soviet advance resumed its advance west. The commander of the XIII Army Corps realised that his Corps needed to retreat if it were to avoid encirclement. The order was given for all Corps units to fall back to the "Prinz-Eugen-Stellung", a series of unmanned defensive positions built in June 1944 which ran partly along the Strypa river about 35 km west of Ternopil. Strong 1st Ukrainian Front attacks throughout 17 July succeeded in capturing parts of the "Prinz-Eugen-Stellung". The 14th Waffen Grenadier Division of the SS joined the combat in an attempt to recapture these lost positions, but after some success ran into a unit of Soviet IS-2 tanks which put an end to the SS advance. Despite repeated warnings from his subordinates, the Corps commander, "General der Infanterie" Arthur Hauffe, did not order further withdrawal, condemning the three XIII Army Corps divisions and Korps-Abteilung C in the Brody salient to their fate.