Every year.

The two things I read every year on this date:

The "as it happened" thread on Metafilter. It was begun barely ten minutes after the first plane hit, just as reports were making their way to the news outlets, and continues for forty-eight hours, non-stop. Note the unbearably painful prescience (or absolutely wrong-headed idiocy) of many of the MeFites. (And oh, those early hours, when we thought that the city was going to need so much blood donation for the "survivors"....)

For Thou Art With Us, Sarah Bunting's exquisite essay recounting her experience of what it was like to be in lower Manhattan on that day, what she saw, what she heard, how she coped.

And now, I add a third: Operation Find Don. It will make sense even if you haven't read "For Thou Art With Us," but will have more resonance if you do.