The Soviet units made rapid progress, moving to cut off the defenders at Kielce. The armored reserves of the 4th Panzer Army's central corps, the XXIV Panzer Corps, were committed, but had suffered serious damage by the time they reached Kielce, and were already being outflanked. The XLVIII Panzer Corps, on the Fourth Panzer Army's southern flank, had by this time been completely destroyed, along with much of Recknagel's XLII Corps in the north. Recknagel himself would be killed by Polish partisans on 23 January. By 14 January, the 1st Ukrainian Front had forced crossings of the Nida river, and began to exploit towards Radomsko and the Warthe. The 4th Panzer Army's last cohesive formation, the XXIV Panzer Corps held on around Kielce until the night of 16 January, before its commander made the decision to withdraw.