After the Russians entered the territory of the Second Polish Republic in autumn 1939, numerous arrests of Poles took place. Many Boryslavians were also arrested, some of them were transported to other places due to the overcrowding of the Boryslaw prison. Before the entry of the Germans in 1941, the Soviets organised the evacuation of most of the prisoners, and on leaving Boryslav they set fire to the prison with dozens of prisoners left there. The bodies of 45 victims, murdered at the end of June 1941 in the local prison, were discovered in the basement of the prison building after the Germans entered Boryslav. Among the victims were 17 Poles, who were buried in a mass grave in the cemetery on Hukowa Gora. The Ukrainian victims were buried in the cemetery in Boryslaw-Tustanovice.

A large cross was placed on the grave of the Poles, with a plaque bearing the names of those buried, but with the approach of the second Soviet occupation in 1944, the plaque was removed and hidden, probably buried somewhere nearby. It has not been found to this day.

In the 1990s the grave was cleaned up by Borysławians (local and those living in Poland). On 1.11.1995, on the initiative of this community, a commemorative plaque was placed on the grave with the inscription: "Here rests the late 17 Poles - / victims of the NKVD crime in Boryslav / 26-28 June 1941 / Honour their memory! / T-wo Zgoda / 1995."

In 2016, on the initiative and funding of the authorities of the Lower Silesian Voivodship, where many Borysławians settled after the war, two granite plaques (one in Polish and the other in Ukrainian) with the names of the victims were placed on the grave.