12

Number of years since the 9/11 attacks.

422,000

Estimated number of New Yorkers currently suffering from post-traumatic stress disorder as a result of the 9/11 attacks.

9

Number of Yale alums who perished at Ground Zero.

2002

The last year Yale observed a campus-wide minute of silence in honor of the attacks.

82.3

Miles between the World Trade Center and Harkness Tower, from which students reported to have seen dust and smoke in the distance on September 11, 2001.

Sources: a) n/a, b) nymag.com, c) Yale Daily News, d) news.yale.com, e) maps.google.com, Yale Daily News