One week after the September 11 terrorist attacks, anthrax letters circulated through US Postal Service facilities on their way to media outlets, political offices, and even private residences. These 9/11 anthrax attacks stoked fear among citizens already reeling from the deadliest terrorist attack on US soil, causing panic and disbelief as the reports multiplied.
As a result of the letters, five people died, and 17 more were treated for anthrax poisoning. The FBI and other investigators carried out an eight-year probe to determine the origins of the anthrax spores, the motives, and who could have carried out such an insidious campaign. The investigation ended in 2010, but no perpetrator was ever officially tried for the attacks. Since the FBI's primary suspect killed himself in 2008, many scientists and legal experts believe we can't know for sure who was responsible for the anthrax attacks. But even without that key detail confirmed, we still have a relatively complete picture of what happened based on the FBI's investigation.
Beginning with letters postmarked September 18, 2001, print and television media offices received strange correspondence from Trenton, NJ, post offices. The handwritten notes contained the date "9-11-01," "DEATH TO AMERICA," "WE HAVE THIS ANTHRAX," and a grainy substance in the envelope with them. The letters were not taken seriously until people began showing symptoms of anthrax poisoning.
The letter sent to NBC's news anchor Tom Brokaw read, "09-11-01. THIS IS NEXT. TAKE PENACILIN (sic) NOW. DEATH TO AMERICA. DEATH TO ISRAEL. ALLAH IS GREAT." The suggestion to take antibiotics prompted speculation of a coded message later in the investigation.
Postmarked October 9, 2001, letters arrived days later at the Washington, DC, offices that handled mail for Senate Majority Leader Tom Daschle (D-SD) and Senator Patrick Leahy (D-VT). The letters also originated from Trenton, NJ, like those received by members of the media. Daschle alerted the press on October 15, and the FBI started collecting mail sent to Capitol Hill to screen for other contaminated letters.
FBI and Environmental Protection Agency hazardous material handlers found the anthrax letter sent to Leahy when going through the 280 barrels of confiscated mail in November 2001. The FBI and EPA created a new technique to search for infected items in the extensive collection of evidence. Wearing hazmat suits and operating in a sealed environment, technicians used air-sampling machines to determine the concentration of anthrax spores in specific barrels.
Bob Stevens was a photo editor for the National Enquirer who worked in the publication's American Media building in Florida. On October 4, 2001, he was hospitalized after inhaling anthrax. Stevens received the anti-anthrax antibiotic Cipro, but did not respond to the medication. He died on October 5, becoming the first US death from anthrax in 25 years.
Over the next two months, 21 more people contracted anthrax poisoning from exposure to the tainted letters, and four of those people died. Two postal workers in the Washington, DC, area died after handling anthrax-laden mail. The final two victims likely contracted anthrax from junk mail contaminated during the sorting process alongside letters sent to actual targets of the campaign. The other 17 - including the 7-month-old child of an ABC News producer - recovered, but those who recovered reported severe side effects from the deadly spores.
After authorities deemed the letters a serious threat to national safety, the FBI began their investigation on October 9, 2011. The case, code-named "Amerithrax," spanned nearly nine years and involved the combined efforts of as many as 30 full-time investigators from the FBI, the Justice Department, and the US Postal Inspection Service. It was the largest investigation in history by particular metrics at the time - law enforcement interviewed more than 10,000 witnesses, and forensic technicians examined more than 6,000 pieces of evidence.