I, too, was looking for this thread today. I think there are many of us who look at 9/11 as a turning point in our lives, the point when our entire futures changed in the blink of an eye. Never forget.
ETA... I can't believe I've never posted my story about 9-11. My brother-in-law is flight attendant for United, flying from Boston, mostly to LA or San Francisco. He was supposed to be working on United flight 175 on 9-11, but he marked out and got someone else to work for him that day, as he'd received a speeding ticket several weeks before and wanted to go to court to protest it, so he was NOT on flight 175 that fateful day. He lost many friends and co-workers, including the flight attendant who took that route for him. Never a year goes by that we don't remember this day, with tears and gratitude.
9-11 started like any other day. My daughter was in 3rd grade, in school, and DH had gone to work. I was in the basement office using the internet, and had come upstairs for coffee. I looked at the TV (it was tuned to Squawk Box on CNBC, with the volume down). I saw the tower burning, with black smoke billowing from the building in front of a brilliant blue sky. I was SO confused... I was thinking that perhaps Squawk Box was talking about a new Terminator movie or something... and then my phone started ringing. It was my youngest sister, frantic, as she knew that it was our BIL's plane that hit the second tower. I didn't know what she was talking about, as I still hadn't heard what had happened. Even when I turned up the volume, I wasn't worried; I knew he'd stayed home from work that day and didn't give it a second thought. Others only knew that that was one of my BIL's regular routes, and they were calling me, concerned, frantic, about what might have happened to our family... but it didn't. We had a close call that day, and my BIL ended up going to Logan to do what he could... $125 for a speeding ticket suddenly seemed like a small price to pay for being alive.
In a strange addendum to this story, this past summer (2018) we were in DC, where we visited the FBI, took the tour, wandered the museum. There, in their tribute to 9-11, is a piece of United flight 175, found among the rubble of the WTC and put on display. It's probably about 3ft by 4ft, all that is left of that giant aircraft. It was surreal to see my BIL's plane there, and know that we were the lucky ones, a family whose 9-11 story did not result in tragedy.