Like I said, I have limited experience. I'm not aware of a cluster of terrorist attacks like that ever before. Correct me if I'm wrong. As a FWIW note, Wikiped

Like I said, I have limited experience. I'm not aware of a cluster of terrorist attacks like that ever before. Correct me if I'm wrong. As a FWIW note, Wikipedia has 3 incidents between 1800-1899, 9 for 1900-1969, and markedly more after that (around 30-40, I didn't count). The world has changed. And/Or, reporting has changed. I'd go with the former.