There are people who want to call today "Patriot Day". Jingoism may be a healthier response to attack than supine surrender, but I find it difficult to embrace bluster, and I carry Gramscian damage of my own.
Personally, I prefer to think of 9/11 as a day of warning, a reminder that civilization is fragile and life is brief. Those terrible, oppressively empty blue skies weighed heavy in the week after the fall of the towers, like the devil's own mono no aware:
Gion shouja no kane no koe
shogyou mujou no hibiki ari.
Shara souju no hana no iro
jousha hissui no kotowari o arawasu.
Ogoreru hito mo hisashikarazu,
Tada haru no yo no yume no gotoshi.
Takeki mono mo tsui ni horobinu.
Hitoe ni kaze no mae no chiri ni onaji.
The song of the bells of the cloister of Gion
Sings of the impermanence of all things.
The split-souled four-limbed sala bush
Her flowers' hue showeth one truth:
That to flourish is to fall
That proud men are so but a while
That pride passeth like a dream of a spring's night
That the valiant are so only to be destroyed
That all shall be blown like dust in the wind.