On the 13.10.1944 Heder was deployed to close a frontline gap with a hastily assembled group of supply troops numbering 400 men. The blocking position was located in the Letniska forest, and the defense was hampered by the absence of heavy infantry weapons and the small number of MGs available. Over the course of three days and nights it was attacked 21 times, 6 of these being preceded by multi-hour drumfire barrages. Two enemy divisions, including 24 AFVs, attacked without pause.
After being encircled Heder formed a hedgehog position in the forest and was cut off from regular resupply for two days.
During this time Heder personally led 15 counterthrusts at the head of the approximately 80 men in the hedgehog position, repeatedly thrusting on his own initiative up to the old blocking position and bringing the enemy heavy losses in the process.
The Letniska forest was held successfully, and after reinforcements had been brought up the old defensive line was once again restored. This success was possible solely on account of the decisiveness, steadfastness and exemplary bravery of Heder himself.
By this action the intended Russian breakthrough towards Jablonna, which would have in turn served as a jump-off point for a further thrust to Modlin, was halted in its tracks.
