Instead Prajapati Daksh due to his ego insulted Sati and her husband Lord Shiva in front of all the guests. Sati could not bear the insult of her husband Lord Shiva by her father, hence she immolated herself.
Lord Shiva upon knowing this plucked a lock of his hair and thrashed it onto the ground thus giving birth to Virabhadra, and Bhadrakali, who then destroyed and decapitated Prajapati Daksha.