In Catania in Sicily, where she was martyred, her veil was removed from her tomb when Mount Aetna threatened and she is credited with saving the city from several eruptions. In other places, bread was blessed on her feast day, perhaps because it looked as if the platter she carries held two loaves. Over time, the two customs were intertwined so that bread blessed on the Feast of St. Agatha was revered for its power to avert fire and was dried and hung in places where fires were likely to breakout.
As the crowd of pagans * fled to the tomb of the virgin, * they took along her veil as defence against the volcanic flames. * In this way the Lord would prove that their deliverance from the danger of fire * had been granted only through the merits of His martyr Saint Agatha.
-Benedictus Antiphon for the Feast of St. Agatha.