From the Synaxarion:
The Holy Martyress Agatha was the daughter of rich and respected Christian parents from the city of Palermo (formerly called Panorum) in Sicily. During the time of the persecution under the emperor Decius (249-251), the city governor of Catana, Centianus, -- having heard about the wealth and beauty of Agatha, sent his soldiers after her to bring her to trial as a Christian. At Catana they housed the saint with a certain rich woman, who had five daughters. They all attempted to provide temptations for Saint Agatha by means of fine clothes, amusements and entertainment, urging her to offer sacrifice to the pagan gods, but the saint would not give in to their tricks, and disdaining all the delights, she prayed the Lord to grant her the strength for the act of martyrdom. At the interrogation under Centianus, the holy martyress was swayed neither by the flattery, nor by the threats, and she was subjected to cruel jeering: they tore at her bosom with iron hooks, and finally, they cut off her breasts. In prison the holy Apostle Peter appeared to her and healed her of her wounds. Led again to torture, Saint Agatha astonished Centianus, in that her bosom was unharmed. They thereupon began to torture her anew. At this moment in the city there began an earthquake, and the earth opened up and swallowed the closest companions of Centianus. The terrified inhabitants rushed to Centianus, demanding that he stop the tortures. Fearing a revolt by the people, Centianus sent Saint Agatha back to prison, where the martyress, in offering up thanks to God, peacefully gave up her soul to the Lord.