On the night of August 2–3, 1936, three weeks into the Spanish Civil War, a Republican Fokker VII bomber piloted by Antonio Martín Luna dropped three 100-pound Spanish-made aerial bombs on the Basilica of Our Lady of the Pillar. One struck the roof of the Coreto chapel; another passed through the roof of the north nave and landed on the pavement; a third fell into the Plaza del Pilar. None of the three detonated.
The bombs were recovered by military engineers and rendered safe. Two of them — cleaned, deactivated, and inscribed with the date — were hung by decision of Cardinal Archbishop Rigoberto Domenech on the pillars of the north nave of the basilica, where they can still be seen today. A subsequent forensic examination could find no fault with the fuses; the pilot Martín Luna, captured after the war, gave conflicting accounts.
The basilica houses the pillar of jasper on which, according to Spanish tradition, the Blessed Virgin appeared to the Apostle James in AD 40 — the oldest Marian shrine in the world. The 1936 bombs are venerated locally as evidence of the Virgin's continuing protection of the shrine.