In the fall of 2001, Aaron Zebley was a 31-year-old FBI agent in New York. He had just transferred to a criminal squad after working counterterrorism cases for years.
His first day in the new job was Sept. 11.
"I was literally cleaning the desk, I was like wiping the desk when Flight 11 hit the north tower, and it shook our building," he said. "And I was like, what the heck was that? And later that day, I was transferred back to counterterrorism."