Guarini's Chapel and the 1997 Fire

The Cappella della Sacra Sindone is a rotunda of black Frabosa marble grafted onto the east end of the cathedral and reached from the choir and from the adjoining Royal Palace, so that the Savoy court and the public could each approach the relic. Guarino Guarini, a Theatine priest and mathematician, took over the unfinished project in 1668 and completed the dome in 1694, stacking six-pointed rings of segmental arches into a cone of light that is one of the boldest structures of the Italian Baroque.

The Shroud was kept in an urn above the central altar. On the night of 11-12 April 1997 a fire, most likely electrical, broke out during preparations for an event; the blaze consumed the chapel and threatened the relic until a fireman, Mario Trematore, smashed the reinforced display case and carried the casket clear. The Shroud survived intact. Restoration of the fire-blackened marble took more than two decades, and the chapel reopened to visitors in 2018. Because the chapel is no longer used to store the cloth, the Shroud is now housed in the cathedral's north transept.