Ezekiel 26:19-20

The Lord further promised that after He destroyed the city by deluging it with great waves of invaders (cf. Ezekiel 26:3), it would die like a person placed in a grave (cf. 31:16; 32:18, 23-25, 29-30). It would go down into Sheol, as it were, and so lose its glory. He pictured the island fortress as submerged beneath a sea of invaders that would bury it (cf. 31:14-18; 32:13-32; Isaiah 14:4-21).

"The most fearful prospect facing ancient mariners was to be caught in a storm and be ’lost at sea.’" [Note: Dyer, "Ezekiel," p. 1279.]

Ezekiel mixed two metaphors for destruction in these verses: waves overwhelming a rocky seaside town, and a person going into the grave (pit, Sheol).