They no doubt see it as a divine symbol that the number ended up being 19, on 11-9 (by the way they read dates), so they will put even more significance on that number
Consider also: the 1 and 9 trains on the IRT, running the West Side, one of the most heavily traveled routes.
Physical, Examinable Evidence
Chapter 74 of the Quran, is dedicated to the PRIME number 19. This number is specifically mentioned as a "punishment" for those who claim that the scripture is human-made (74:25). It is also called one of the greatest sings or miracles (74:35).
In 74:31, the purpose of this number is described: to remove all doubts regarding the authenticity of the Quran, to increase the faith of the believers, and to be a scientific challenge for hypocrites and disbelievers.
http://www.geocities.com/aliadams/19.htm