Ali Soufan left the FBI six years ago, and today he runs a security consulting company based in New York. He told Lara Logan that he hasn't been to Ground Zero since the first anniversary of 9/11.
"Maybe I'm one of these people who didn't get over it," Soufan said.
"Can you tell me why?" Logan asked.
"You know, maybe part of me feels guilty. Maybe part of me feels some sort of responsibility of what happened," Soufan said.
"But you did your best. You gave your all. Why would you feel guilty?" Logan asked.
"If you want to be truthful with yourself," Soufan said, "[it's] very difficult...not to kind of like feel that...maybe I could've done something."
"Is that why it's hard for you to go to Ground Zero?" Logan asked.
"Yeah, actually, I went there once, on the first anniversary but that's it," Soufan said.
"It's hard for anyone to go there," Logan said.
"Yeah, absolutely," Soufan agreed.
"Why so hard for you, Ali?" Logan asked.
"I don't know," Soufan said, looking as if he was about to cry. "I don't know."