because she had fourteen children (Niobids), seven male and seven female, while Leto had only two. She further mocked Apollo's effeminate appearance and Artemis' manly appearance. Leto, insulted by this, told her children to punish Niobe. Accordingly, Apollo killed Niobe's sons, and Artemis her daughters. According to some versions of the myth, among the Niobids, Chloris and her brother Amyclas were not killed because they prayed to Leto. Amphion, at the sight of his dead sons, either killed himself or was killed by Apollo after swearing revenge. A devastated Niobe fled to Mount Sipylos in Asia Minor and turned into stone as she wept. Her tears formed the river Achelous. Zeus had turned all the people of Thebes to stone and so no one buried the Niobids until the ninth day after their death, when the gods themselves entombed them. When Chloris married and had children, Apollo granted her son Nestor the years he had taken away from the Niobids. Hence, Nestor was able to live for 3 generations. Building the walls of Troy Once Apollo and Poseidon served under the Trojan king Laomedon in accordance to Zeus' words. Apollodorus states that the gods willingly went to the king disguised as humans in order to check his hubris. Apollo guarded the cattle of Laomedon in the valleys of mount Ida, while Poseidon built the walls of Troy. Other versions make both Apollo and Poseidon the builders of the wall. In Ovid's account, Apollo completes his task by playing his tunes on his lyre. In Pindar's odes, the gods took a mortal named Aeacus as their assistant. When the work was completed, three snakes rushed against the wall, and though the two that attacked the sections of the wall built by the gods fell down dead, the third forced its way into the city through the portion of the wall built by Aeacus. Apollo immediately prophesied that Troy would fall at the hands of Aeacus's descendants, the Aeacidae (i.e. his son Telamon joined Heracles when he sieged the city during Laomedon's rule. Later, his great-grandson Neoptolemus was present in the wooden horse that lead to the downfall of Troy). However, the king not only refused to give the gods the wages he had promised, but also threatened to bind their feet and hands, and sell them as slaves. Angered by the unpaid labour and the insults, Apollo infected the city with