The Culavamsa says Kassapa walled up his father alive after the king showed him a reservoir as his only treasure

King Dhatusena of Anuradhapura had two sons. Moggallana was the son of the royal consort and the heir. Kassapa was the son of a concubine. The king made his sister's son commander of the army. After a quarrel in which this nephew mistreated the king's daughter, the king had the nephew's mother burned. The nephew turned Kassapa against his father, and together they took the king prisoner alive. Moggallana fled to India to raise troops. The nephew told Kassapa that the king had hidden treasure in the palace. The Culavamsa records that Dhatusena asked to bathe in the Kala Wewa, the reservoir he had built, and then die. At the tank he said, "This here, my friends, is my whole wealth." Kassapa ordered, "Slay my father." The king was stripped, put in chains and walled up with clay. Kassapa moved his court to the rock of Sigiriya out of fear of his brother. In the eighteenth year of Kassapa's reign, Moggallana returned from India with an army. When the battle turned, Kassapa cut his own throat with his dagger and sheathed the knife. Moggallana took the throne. The Kala Wewa and the ruins of Sigiriya still stand^†.