* The doctor's inability to communicate: The poem opens with the doctor stating, "I can't explain it." This suggests a profound sense of helplessness and inability to comprehend the scale of the destruction.
* The silence of the victims: The poem describes the victims as "unblinking" and "still" which suggests their silence is a product of shock and trauma. Their faces "fixed like masks" further emphasizes their inability to express what they have witnessed.
* The overwhelming nature of the event: The poem uses imagery like "a thousand suns" and "a blinding light" to convey the magnitude of the blast. This overwhelming experience could have easily rendered those present speechless.
In essence, the silence in the poem is a manifestation of the shock, trauma, and overwhelming nature of the event. It represents the inability to comprehend the horror that has unfolded and the profound impact it has had on everyone present.