Last week, the Army scientist that investigators believe was responsible for those attacks, Dr. Bruce Ivins, committed suicide.
And while we'll never know for sure why a man who was supposed to stop bioterrorism might have engaged in it himself, the New York Times reports that he may have just been trying to draw attention to his field and draw more money for his research.
If that was Ivins' plan, in a sick way, it's begun to work. Billions have been spent on developing and stockpiling vaccines.
But more labs mean more people who could deliver classified information into the wrong hands. Washington needs to take this threat seriously so the next 9/11 isn't planned in a government lab.
That's a page from my notebook. I'm Katie Couric, CBS News.