A note published in the journal "Sztuki Piękne",1931, no. 10, p. 392 (public domain, reprinted from the Library of the University of Silesia, Katowice) contains a description by arch. Juliusz Kłos's description of the work carried out and its results in the Chapel of St Casimir in Vilnius, which, among other things, ruled out that the chapel was the burial place of Alexander Jagiellon and Barbara Radziwiłłówna. Eventually, later that year, researchers managed to find the tombs in the Cathedral.

A modernised reading of the text

On the basement of the Chapel of St Casimir in the Basilica.

The Historical and Artistic Committee of the Committee for the Rescue of the Basilica of Vilnius met in the St Casimir's Chapel in the composition of Prof. Dr. M. Morelowski, deputy chairman, Rev. Fr Sawicki, rector of the Basilica, Prof. J. Kłos, architect, manager of the restoration works, J. Hoppen, secretary of the Committee, I. Liziębła, M. Brensztajn and members of the Technical Committee of the Committee: J. Borowski, arch. S. Narębski to familiarise themselves with the current status of the works.

The manager of the works, Prof. J. Kłos, reported in detail on the results of the work to date. After the marble floor had been removed and the rubble underneath had been cleared away, it became clear that there had never been a vault under the St Casimir's Chapel. When the foundations of the chapel were being laid, cross vaults were planned, traces of which can be seen in the shield arches, made in three in each wall, and in the windows, which brought in light from outside, but this intention was apparently soon abandoned, most probably because of the ground water above the sole of the foundations.

Clear evidence of this is the absence of any vaulting on the walls, as well as the fact that the foundations of the former Vollovich Chapel were left inside the chapel's vaults, which would have had to be removed to make way for the projected vaults. These foundations show a medieval masonry thread, made of large-format bricks laid in Polish bond. It therefore follows that the vaults were abandoned already during the construction of the chapel and the space between the foundations was filled in with rubble.

Consequently, the window in the chapel's eastern wall was not caulked either, but was backfilled with rubble. It is therefore impossible to think that the coffins containing the royal corpses (of King Alexander, Elisabeth and Barbara Radziwill) were moved under the chapel, for which there is no historical evidence whatsoever.

The wall uncovered under the chapel's altar, irregularly and carelessly laid of fieldstone, is probably only the foundation for the altar's podium, if only because it is very shallow, making it difficult to suppose that royal tombs could have been located there. The Commission decided to dismantle this foundation carefully, believing that it might contain an urn containing the heart of Władysław IV.

The President of the Commission expressed his heartfelt thanks to Monsignor A. Sawicki, the rector of the Basilica, and Prof. J. Kłos, the supervisor of the works, for their diligence in a matter of such importance, after which the Commission approved the programme of the forthcoming works and deemed it necessary to demolish the sub-altar foundations. It was also concluded that the historical and archival research carried out up to that point was in complete agreement with the results of the work carried out, since the supposition that the royal remains had been moved to the Chapel of St Casimir was based on nothing more than conjecture.