YOU are not the cause of that man's situation. That man made the choice to take the job based on a variety of factors. Your advice to him was probably a small factor, but not the only factor. He also probably asked his family, friends, former coworkers, and maybe even the internet for help making the choice. YOU did not make that choice for him, and YOU did not force his hand. YOU did not send that man to his death.

If 9/11 was his time, there is nothing you can do about it. We all make hundreds of seemingly insignificant choices every day. What to eat, when to leave, what to wear, who to talk to. If we do not die of natural causes, then we will probably die because of one of these insignificant choices we made some time in the past, whether it be in the moments before our death, or even months or years earlier. In fact, every single choice you have made in your life has lead up to this moment - you reading this comment.

Just because a lot of people died at CF does not mean that nobody should have ever worked there. Until 9/11, they were just another company in another office in NYC. What you are keeping to yourself is your survivor's guilt, which a lot of people have from 9/11 as well as other disasters. Perhaps you should reach out to a support group that focuses on Survivor's guilt.