On 4 July 2023, the 80th anniversary of the death of Gen. Władysław Sikorski, IPN Deputy President Mateusz Szpytma Ph.D., and the Director of the Institute's Cracow Branch Office, Filip Musiał Ph.D., laid flowers in St. Leonard's crypt on Wawel Hill, by the sarcophagus of the Commander-in-Chief.

Tribute to the Prime Minister of the Polish Government in Exile was also paid by Łukasz Kmita Lesser Poland Voivode and a representative of the Office for War Veterans and Victims of Repression. A short prayer was said by the Wawel Cathedral Parish Priest, Rev. Paweł Baran Ph.D.

Gen. Sikorski died on 4 July 1943. The Liberator in which he was flying fell into the sea 16 seconds after takeoff from Gibraltar. Only the pilot was rescued. The British committee investigating the accident ruled out sabotage and pointed to mechanical failure as the cause of the crash. As documents from the investigation remain classified, there has long been speculation about other causes of the accident. The British, German and Soviet intelligence services, as well as some Polish political circles unfavorable to Sikorski, have been accused of carrying out the assassination of the Polish Prime Minister.