I know someone who works in Manhattan, and for several hours I didn't know if she was at the WTC at the time it happened. I found out hours later that she was okay, but she knew some people who'd died there that day. I found out a few days later that out my company's NY branch had sent some techs over that morning to work on computers for one of the companies in the WTC, but only one of them made it on time due to traffic. The others survived. I didn't know the person, but it's still difficult. I can't imagine what it must have been like for his colleagues.