I am in Red Hook, Brooklyn, just across the harbor from Downtown Manhattan. I have dropped off my son on his first full day of school. The day seamlessly conflates with that morning of a day sixteen years before. The Twin Towers are burning. The sky, that sharp and flawless painful blue, is the same as that day. In horror, we see everything so clearly. We expected, we suspected nothing. There is not a cloud in the sky, only smoke and fire and people.