This has not happened anywhere other than your imagination. You mean "if" not "when."
Fortunately, it was well documented. Per the New York Times:
https://www.nytimes.com/1972/12/02/archives/letterbombs-mail...
alt Hacker News
Fortunately, it was well documented. Per the New York Times:
https://www.nytimes.com/1972/12/02/archives/letterbombs-mail...