In the early morning of May 10, 1943, a voracious fire consumed much of the building and the collections of the then National Library of Peru. A few days after the incident, the government appointed a Pro-Reconstruction commission. In July of the same year, Jorge Basadre assumed the leadership of BNP.
In January 1944, the ceremony of the laying of the first stone was carried out, coinciding with the end of the work of preparing the plans and with the expropriation of a piece of land that would allow the expansion of the library along the Old Cascarilla Street, today block 4 of Abancay Avenue.