I was channel surfing and started watching a rerun of Law and Order SVU and saw the WTC in some background shots so I instantly knew the show was from 2001 or earlier. It is a moment that divides time into before and after.
Both the Toronto Sun and the San Francisco Examiner had the best front pages for the event. I am guessing since the Sun is in the eastern time zone and is a morning paper it might have been the first of the two but not certain.