New York City. Spores of Bacillus anthracis, the bacterium that causes anthrax, appear in six U.S. states.
By month’s end: 3 tainted letters, 17 infections, 4 deaths.
The one death in New York has caused particular attention, because it has not been linked to any known source of the bacterium.
Anthrax is not contagious, and luckily the bioterrorism was not as widespread as it might have been. No exposure, no infection.