Rock layers were found containing 30 kg of radioactive elements that had a half life of 5 million years. How old were the rock layers if scientists determined that the samples had originally contained 120 kg of the radioactive materials?

These lines describe the loss of the identity of the city though the loss of the empire state buildings.

Explanation:

The world trade center ad the twin towers of the empire state building had been the center and the symbol of US commerce for a long time and were a reminder of its financial power.

They were attacked and torn down and thus the poem concerns with the twin towers.

The poem talks from the perspective of a bird in the sky or perhaps anything in the skyline that misses the grandeur of the two buildings talking about the loss of what was unthinkable to lose.