loyal to Carthage and the most important economically. The city's prosperity was based on trade and fishing, which resulted in an unusual lack of agriculture and the area immediately around the city was thickly forested, even close to the gates. The city was surrounded and blockaded, and siege engines set up. These made a breach in the walls which the Romans stormed, capturing the outer town and giving no quarter. The inner town promptly surrendered. The 14,000 inhabitants who could afford it ransomed themselves and the remaining 13,000 were sold into slavery. Much of western inland Sicily then went over to the Romans: Ietas, Solous, Petra, and Tyndaris all came to terms. In response to these events on Sicily the Carthaginians despatched Hasdrubal to Sicily, probably in 254 BC, with the 5,000 infantry and 500 cavalry they had earlier withdrawn and a reinforcement of 140 elephants. The Romans avoided battle between 254 and 251 BC; according to Polybius because they feared the war elephants which the Carthaginians had shipped to Sicily. Bagnall suggests that survivors of the battle against Xanthippus passed on "horrific stories" of the effectiveness of the Carthaginian cavalry and elephants in open battle. In consequence Hasdrubal, probably with a smaller army than the Romans, dominated the plains; the Romans stayed on higher and broken ground, where much of the effect of the cavalry and elephants would have been nullified. Both sides declined to face the other on their favoured terrain. Hasdrubal spent the time drilling and training his army, including the elephants. In 252 BC the Romans captured Thermae and Lipara, which had been isolated by the fall of Panormus. Battle of Panormus In late summer 250 BC Hasdrubal, hearing that one consul (Gaius Furius Pacilus) had left Sicily for Rome with half of the Roman army, marched out from the major Carthaginian stronghold of Lilybaeum towards Panormus with 30,000 men and between 60 and 142 elephants. Halting some distance away, he devastated the harvest in the territories of Rome's newly allied cities, in an attempt to provoke the Roman commander, Lucius Caecilius Metellus, into battle. The Roman troops amounted to two legions, and they had been dispersed to gather the harvest. Metellus withdrew them in front of the advancing Carthaginians and they retreated into Panormus. This timidity was what Hasdrubal had come to expect, and he advanced down the Oreto valley, continuing to despoil the countryside.