The Night of Wailing was the name given to the night during which Nexal was destroyed and many of the inhabitants turned into monsters. Several prophets of Qotal foresaw the events before they occurred and the priestess Erixitl attempted to prevent the calamity.
Events were set into motion when Cordell's lover and mage Darien killed the Nexalan ruler Naltecona. This caused the native Nexalan warriors to attack Cordell's native allies. During the ensuing battle, Domincus, Cordell's bishop, was captured by Nexalans and sacrificed to Zaltec. The sacrifice of his priest infuriated Helm and he clashed with Zaltec, which resulted in the explosion of Mount Zatal, which overlooked the city. The eruption of Mount Zatal toppled many of the buildings in Nexal, including some of the pyramids, and caused much of the city to sink back into the lakes on which it was built.
Lolth took advantage of the chaos and cursed Nexal's warriors, turning them into orcs, ogres, and trolls. As punishment for their lack of faith, she turned the Ancient Ones from drow into driders. The few Nexalans who survived the disaster fled the city and it was left in ruins.