 In the days before the arrival of the American army, thousands of the prisoners were forced to join the evacuation marches.Thanks in large part to the efforts of Polish engineer (and short-wave radio-amateur, his pre-war callsign was SP2BD) Gwidon Damazyn, an inmate since March 1941, a secret short-wave transmitter and small generator were built and hidden in the prisoners' movie room.On April 8 at noon, Damazyn and Russian prisoner Konstantin Ivanovich Leonov sent the Morse code message prepared by leaders of the prisoners' underground resistance (supposedly Walter Bartel and Harry Kuhn)