Here is an ASTROCARTOGRAPHY MAP of the moment the first plane smashed into the North Trade Tower in New York City on September 11, 2001 at 8:45 AM.

Attack Map

The chart of the event, like the map, does not hold the whole story:

Attack Chart

The event makes more sense when placed in a biwheel with the US Independence Day Birth Chart in the center, representing how the attack affected the American people:


I will briefly point out a few things to notice however:
1) Note that Pluto sits right on top of the American Ascendant! OUCH!
2) It's opposition to Saturn is a big piece of this puzzle (See the August/September issue of the Mountain Astrologer for an excellent article by Rob Hand on this opposition) and Saturn was conjunct the American Mars/Uranus midpoint as if pulling a deadly trigger in the 7th house of "open enemies".
3) America's "money planets" - Jupiter and Venus were being touched by the fateful North Node.
4) Neptune was conjunct the American South Node (that which has already been put in place) in the second house of money matters and values, for Americans are generally unaware of how offensively our trade decisions, corporations, and political dominance affect the rest of the world.
5) Transiting Uranus hit the American Moon - our emotions, our homeland, and our sense of security were all terribly disrupted by the shocking element of surprise generated by this attack.

and there's another biwheel of the attack as it affected a different chart of America called "Scorpionic America", cast for the adoption of the Articles of Confederation

If you'd like to read a more detailed explanation of the astrology of the attack, you can read "When the Twin Towers Fall in the City of York", a more indepth look at the celestial influences of that horrific and historic event.

This article includes reference to a third biwheel, that of the attack and the New York Stock Exchange's birth chart here.