I was standing in the aisle by my desk chatting with two coworkers at 8:45 a.m. when the first plane struck our building.
Although we had practiced thousands of fire drills, we had never left the 27th floor. We had always been told that if anything were to happen, someone would tell us what to do.
It took us nearly 45 minutes to walk down the last 20 floors. We had no idea that a second plane had hit the other tower as we made our way down.
Before I could figure out what was happening, I heard a tremendous roar, a sound unlike anything I've ever heard before or since. Right before my eyes, the south tower began to melt down to the ground.
As I hung up the phone, I heard another tremendous roar in the distance. I turned around to see the north tower collapsing down on itself.
I began my walk uptown, more than 70 blocks. It was such an eerie journey. Huge crowds of people were walking, and yet it was so quiet.
I have never been back down to the World Trade Center. I don't think I can ever return.
This story was originally published on September 7, 2016.