Time.com is reporting on a book excerpt about How an Al-Qaeda Cell Planned a Poison-gas Attack on the N.Y. Subway. I have always wondered why we protect the airplanes like crazy yet we do nothing in the world's subway systems.

Couple of interesting excerpts:

The plot was called off by Bin Laden's No. 2 only 45 days from zero hour, according to a new book by Ron Suskind.

Ali revealed that Ayeri had visited Ayman Zawahiri in January 2003, to inform him of a plot to attack the New York City subway system using cyanide gas. Several mubtakkars were to be placed in subway cars and other strategic locations. This was not simply a proposal; the plot was well under way. In fact, zero-hour was only 45 days away. But then, for reasons still debated by U.S. intelligence officials, Zawahiri called off the attack. "Ali did not know the precise explanation why. He just knew that Zawahiri had called them off."

Easily constructed and concealed, mass casualties were inevitable if it could be triggered in any enclosed public space.

Read the full article here:

http://www.time.com/time/nation/article/0,8599,1205309,00.html