Titus Livius (Livy), The History of Rome, Book 24
Frank Gardener Moore, Professor Emeritus in Columbia University, Ed.

19. Quintus Fabius, the consul, had his camp near Casilinum, which was held by a garrison of two thousand Campanians and seven hundred of Hannibal's soldiers. [2] In command was Statius Metius, who had been sent by Gnaeus Magius, of Atella (who was the medix tuticus¹ that year), and Metius had armed slaves and plebeians without distinction, in order to [p. 235]make an attack upon the Roman camp while the² consul was occupied with the siege of Casilinum. [3] Of all this nothing escaped Fabius. So he sends word to his colleague at Nola that he needs the other army, to face the Campanians while Casilinum was being besieged: [4] either Marcellus should leave a suitable garrison at Nola and come in person, or if Nola held him back and there was still danger from Hannibal, he would himself summon Tiberius Gracchus, the proconsul, from Beneventum. [5] On receiving this message Marcellus left two thousand soldiers as a garrison at Nola, and with the rest of his army came to Casilinum; and upon his arrival the Campanians, who were already bestirring themselves, became inactive. [6] So began the siege of Casilinum by the two consuls. Since in this operation the Roman soldiers rashly approaching the walls were receiving many wounds and the undertaking was not successful, Fabius thought that they should give up a small affair which was as difficult as great ventures, and that they must leave the place, since greater matters were impending. [7] Marcellus, saying that, while there were many places which great generals ought not to attack, yet, once the attack has begun, they should not give them up, since reputation has great influence in both directions, carried his point, not to depart while their attempt was unsuccessful. [8] Then while sheds and all other kinds of siege-works and apparatus³ were being brought up, and the Campanians were begging Fabius for permission to go to Capua in safety, after a few had left the city, Marcellus occupied the gate by which they were leaving. [9] And a general slaughter began,⁴ first around the gate, and then, as the troops burst in, [p. 237]even inside the city. About fifty Campanians who⁵ had left the city first sought refuge with Fabius and, escorted by his men, reached Capua. [10] Casilinum was captured, as opportunity offered during the conversations and the delay due to those who begged a promise of protection. And the captives, whether Campanians or of Hannibal's soldiers, were sent to Rome and there imprisoned. [11] The mass of the townspeople were distributed among the neighbouring communities to be guarded.