I was in the Oitzar HaSeforim (library) in Yeshivas Mir in Yerusholayim. There must of been 10-20 of us. Everyone was minding their own business, each one absorbed in their sefer, when all of a sudden one bochur jumped up from his seat, staring at his cell phone, and with a look of shock and horror screamed, ” A plane just hit the World Trade Center!” We all looked up, and stared, waited for more news, but he just ran out. 10 seconds later we heard a “bang” in the Bais Medrash downstairs. The gabbai who gave a ‘klap’ by the amud, started to say a kappital tehillim aloud.
I was a bachur back then, from Canada, and did not know that the WTC and the Twin Towers were one and the same.