The 2001 anthrax letter attacks killed five people and remain the only lethal use of anthrax as a bioweapon outside of warfare in U.S. history.
Key Facts
- Deaths
- 5 people
- Infected
- 17 people
- Attack period start
- September 18, 2001
- Investigation closed
- February 19, 2010
- Government lawsuit settlement
- 2.5 million USD
- Declared sole perpetrator
- Bruce Edwards Ivins
By the Numbers
Location
Cause → Event → Consequence
One week after the September 11, 2001 attacks, an unknown perpetrator — later identified by the FBI as government biodefense scientist Bruce Edwards Ivins — prepared letters containing Bacillus anthracis (Ames strain) spores and mailed them to news media offices and U.S. senators Tom Daschle and Patrick Leahy.
Beginning September 18, 2001, anthrax-laced letters were received at multiple media outlets and Senate offices, killing five people and infecting seventeen others. The FBI launched one of its largest investigations in history, initially focusing on bioweapons expert Steven Hatfill before shifting attention to Ivins, who died by suicide in July 2008. Federal prosecutors named Ivins the sole perpetrator on August 6, 2008.
The attacks prompted major biosecurity reviews and a prolonged, controversial FBI investigation that was formally closed in 2010. A 2011 National Academy of Sciences report questioned the scientific basis for naming Ivins as the perpetrator. Iowa State University's anthrax archives were destroyed, hampering research. The government settled a lawsuit from the first victim's widow for $2.5 million with no admission of liability.
Belligerents & Mobilization Analysis
Side A
1 belligerent
Side B
1 belligerent