http://www.snopes.com/rumors/taxi.htm

The "Urban Legends" people have taken it upon themselves to give us a lecture about "tolerance", and there is not a single shred of evidence to dispute the perception of lack of cabs in lower Manhattan on the morning of 9/11.

If they could produce a few people, of ANY nationality, that saw cabs down there on 9/11, they would do well to make it public. Apparently, of the many tens of thousands of people that were there that day, NOBODY saw any.