It feels like yesterday and it feels like a lifetime ago. The images and the emotions are still so vivid and raw in my head, yet I can't even remember what it was like to be able to bring bottles of waters through airport security.
Today is a day of remembrance. For many, sharing stories is a way of healing; there is comfort in knowing that others remember the same event as vividly as you do and were just as affected.
Here, some of the top players share their stories, remembering where they were on Sept. 11, 2001:
Roger Federer: "I was back in Switzerland. I don't remember how I played that year, but I was practicing back in the National Tennis Center in Switzerland. I was in the gym, and I think someone told me something was happening on the phone, I think.
"Went up to see the TV and was kind of watching the whole thing unravel. It was disturbing to watch in some ways because nobody knew what was going on. You figure many people passed away. So every year since hasn't been the same coming back to New York.
"I never went to Ground Zero. Never felt like I had to go see that place. But I'm sure they're going to create something nice to remember all those people."
Andy Roddick: "I actually had tickets to a concert in New York City that night, and for some reason I left the night before. I was in New York, and I woke up the next morning at my parents' house and just saw it. Like anybody else, you're just shocked. I didn't know what to think. You know, it was a place you were the day before. It was just really weird.
"But I will say this: The six months to a year after that, I probably haven't been prouder of the people in this country as far as the way they came together. I wish it would have had a little bit more staying power. Hopefully the 10-year mark will bring back some of those feelings of unity that we did have after that. I don't think it's a bad thing to remember."
Rafael Nadal: "I remember exactly what I did that day. I was playing a match to win my first [ATP ranking point], and I lost that match with 13 match points. Just after that match I saw the tragedy on TV. I was really sad about my match, because the first point always is really important. But when I came back to the locker room and I saw that on TV, I really forget the match in one second, no? I was there in the Twin Towers a few months before, in the top. On the TV, that's probably one of the views that had a bigger impact on myself."
Serena Williams: "I was in D.C. at the time, and I just remember seeing a lot of Army trucks. It's hard to believe it's 10 years later, but, you know, it's good. Good we are kind of coming together and New Yorkers and New York has been so strong."
Samantha Stosur: "I was playing 10,000s in Japan. I woke up to the TV or one of the other Aussie girls there calling the room and saying, 'Turn on the TV and look what's going on'. Obviously it was unbelievable. I was only 17 at the time. There were four or five of us traveling around in a group together and had no idea what was going to happen. We all thought planes aren't going to fly ever again and didn't know.
"Obviously watching those images, going out to play your matches at a 10,000 event all of a sudden became pretty irrelevant. It's kind of strange to be back here in New York on the 10th anniversary. It's great to see how people have moved on. Obviously it was a really sad time, but obviously everyone's getting through it."
Caroline Wozniacki: "I was actually practicing [in Denmark], and I was going home from practice and my brother was in his room. He was watching TV. I asked him, 'What are you watching? What movie is that?' He said, ‘It’s not a movie. It’s happening.’ Me and my dad said, 'No, come on. Stop joking. It’s not funny.' We were changing the channels and it was just on every channel. We were pretty much shocked what was going on. So many people died. Ten years. It’s gone past very fast.”Vera Zvonareva: