@astrotheological,
It is estimated that between 400 and 500 Jews died in the attacks on the World Trade Center on 9/11. The exact number is not known, since official record-keeping does not list the religions of the victims.
The Jewish Week
http://www.thejewishweek.com/bottom/specialcontent.php3?artid=362
The figure would have been even higher had it not been for the fact that many Orthodox Jews went to work an hour later because of the Selichot prayers recited in the days before the Jewish New Year. This is probably the one fact that has been exacerbated into the conspiracy that hardly any jews died on 9/11.
Jerusalem Center for Public Affairs
http://www.jcpa.org/phas/phas-13.htm
Here are two excellent articles which debunk the widely-spread story alleging that thousands of Jews stayed home on September 11th because they had been warned in advance of the attack:
Snopes: Rumors
http://www.snopes.com/rumors/israel.htm
Slate: 4,000 Jews, 1 Lie
http://slate.msn.com/id/116813
It is possible that some who wish to believe that 9/11 was an Israeli conspiracy will not accept all of the reference sources listed above. If that is the case, the plainest evidence that many Jews died in the World Trade Center is the list of the names of the dead:
The official New York City 'Missing Persons List' does not categorize victims by their religion or nationality. But ask families with names like Adler, Aron, Berger, Bernstein, Cohen, Eichler, Eisenberg, Feinberg, Friedlander, Goldstein, Greenstein, Horwitz, Jablonski, Kestenbaum, Kirchbaum, Kleinberg, Levi, Levine, Mayer, Rosenberg, Rosenblum, Rosenthal, Sachs, Safronoff, Schwartz, Shulman, Shwartzstein, Silverstein, Solomon, Steinman, Temple, Weil, Weinberg, Weingard, Weinstein, Weiss, Zukelman.
Why didn't they get a conspiratorial cell-phone message warning them to stay home?