September 11 is also the beginning of the Ecclesiastical (Church) Year on the Coptic calendar.
http://www.missionstclare.com/english/people/sep11o.html
Just a cursory read of the Orthodox Matins for that day reveals a theme of prayers for peace and victory:
http://www.antiochianladiocese.org/files/service_texts/other_commem/indiction/Sept-01-ORTHROS.pdf
(Start reading on page 6)
September 11 was NOT random.
The jihadists were attempting to poke a finger in the eye of Almighty God!
It looks like a confluence of angry rages.