In the third episode of the season, 'Hazard Pay', Walter White brings up the Icarus myth when considering whether Mike was going to prove too difficult a partner to keep alive. Mike is dead now, a common fate among Walt's associates. So many have been lured in by the promise of Heisenberg's blue meth, willing to go higher and higher despite knowing the risks. Walt is not Icarus, but Daedalus, the boy's father and the engineer who built the wings to allow his son to escape Crete. Daedalus is a genius perpetually betrayed by his own hubris: he is locked away in a labyrinth of his own construction, then later creates the instrument by which he sends his son to his death.
Walt's blue meth is a creation of equal magnificence, and bears no less deadly a curse. Watching Mike die needlessly at his hand was the first moment Walt felt something approaching awareness of the horror he had dedicated so much of himself to creating.