Found this article:
'A total of 2,071 occupants of the World Trade Center died on September 11, among the 2,749 victims of the WTC attacks. According to an article in the October 11, 2001, Wall Street Journal, roughly 1,700 people had listed the religion of a person missing in the WTC attacks; approximately 10% were Jewish. A later article, in the September 5, 2002, Jewish Week, states, "based on the list of names, biographical information compiled by The New York Times, and information from records at the Medical Examiner's Office, there were at least 400 victims either confirmed or strongly believed to be Jewish." This would be approximately 15% of the total victims of the WTC attacks. A partial list of 390 Cantor Fitzgerald employees who died (out of 658 in the company) lists 49 Jewish memorial services, which is between 12% and 13%.
This 10-15% estimate of Jewish fatalities tracks closely with the percentage of Jews living in the New York area. According to the 2002 American Jewish Year Book, 9% of the population of New York State, where 64% of the WTC victims lived, is Jewish. A 2002 study estimated that New York City's population was 12% Jewish. Forty-three percent of the WTC victims lived in New York City. Thus, the number of Jewish victims correlates very closely with the number of Jewish residents in New York. If 4,000 Jews had not reported for work on September 11, the number of Jewish victims would have been much lower than 10-15%.'