The attacks followed a week after the September 11 attacks , which had caused the destruction of the World Trade Center in New York City , damage to The Pentagon in Arlington , Virginia and the crash of an airliner in Shanksville , Pennsylvania . The anthrax attacks came in two waves . The first set of anthrax letters had a Trenton , New Jersey postmark dated September 18 , 2001 . Five letters are believed to have been mailed at this time to : ABC News , CBS News , NBC News and the '' New York Post '' , all located in New York City and to the '' National Enquirer '' at American Media , Inc. ( AMI ) in Boca Raton , Florida . Robert Stevens , the first person who died from the mailings , worked at the '' Sun '' tabloid , also published by AMI , died on October 5 , 2001 , four days after entering a Florida hospital with an undiagnosed illness that caused him to vomit and be short of breath . Only the '' New York Post '' and NBC News letters were found ; the existence of the other three letters is inferred because individuals at ABC , CBS and AMI became infected with anthrax . Scientists examining the anthrax from the '' New York Post '' letter said it appeared as a clumped coarse brown granular material looking like dog food
September 11 attacks
September 11 attacks
2001 anthrax attacks