A demon named Pralamb had escaped unharmed in the battle fought between the deities and demons. As the deities were busy installing Shivalingas at different places, Pralamb started to torment their families in their absence. The deities got this information from Kumud who appeared at the time when the deities were digging up a reservoir near ‘Siddheshwar’ temple. All the deities requested Kartikeya to do something. Kartikeya released his fiery weapon, Shakti in the direction of Pralamb. Shakti pierced the heart of earth and went right up to Patal loka where Pralamb lived with the surviving demons. All the demons were killed within few moments.
A long tunnel had been created as the impact of Shakti’s penetration of the earth. This tunnel was later on filled up with the water of Patal Ganga and became famous as ‘Siddha-koopa.’