Which event in Ovid's myth does Auden focus on in his poem?

Auden centered his poem around Icarus's descent after the melting of his wings. W. H. Auden observed a painting titled The scene with Icarus's fall at Musée des Beaux-Arts de Bruxelles.

In that artwork, a plowman is seen working, a shepherd overseeing his flock, numerous ships, and in the lower right corner, a pair of white legs moving beneath the water. Everyone appears to remain engrossed in their tasks, perhaps oblivious to the fate of the man in the lake. Auden drew inspiration from that scene to write about humanity's apathy towards suffering