There are a lot of 9/11 poems in the world

And a lot of them are bad. So I am sparing you by posting Dorianne's "Cello" instead.

Cello

When a dead tree falls in a forest
it often falls into the arms
of a living tree. The dead,
thus embraced, rasp in wind,
slowly carving a niche
in the living branch, shearing away
the rough outer flesh, revealing
the pinkish, yellowish, feverish
inner bark. For years
the dead tree rubs its fallen body
against the living, building
its dead music, making its raw mark,
wearing the tough bough down
as it moans and bends, the deep
rosined bow sound of the living
shouldering the dead.

(Dorianne Laux, from Facts About the Moon, 2007 WW Norton)