After making his nephew Perdix lose his balance and fall off the roof of his house and losing his beloved son Icarus, he fled into the Labyrinth. After killing his nephew, he was branded with the mark of a partridge (which Perdix had been turned into) by Athena. While in the Labyrinth, he used a technique (suggested by Perdix) the allowed him to avoid dying by transferring his consciousness into a new body five times throughout history. The consciousness is referred as the 'animus,' the soul and center of a human being. Edit
During his 5th life and during the second Olympian War. After much soul-searching, he asks to be killed by Nico di Angelo. Nico does this by releasing his spirit in order to destroy the labyrinth and halt Luke's invasion of Camp Half-Blood through Zeus' Fist. When Daedalus dies, the Labyrinth is destroyed because it is tied to his life force. It is said that he is now creating roads and overpasses in the Fields of Asphodel in the Underworld to help ease the traffic congestion and is allowed to visit his son, Icarus, and his nephew Perdix on weekends.