"Ashes" and "dust", by definition, conjure images of disintegration. The falling rain,
the falling sound, and the statement that the "towers are yesterday" all further
contribute to that theme. "The sky is dust" and "Here are the ashes", along with the
narrator's concern with weeping, tears, and the loss of tomorrow, indicate that the
disintegration is both physical and metaphorical.
Hum