Stocks tumbled in late-morning trading on Friday as worries about the possibility of more attacks on the United States roiled Wall Street. 
A New York employee of broadcaster NBC has tested positive for anthrax, a bacteria whose spores are potentially deadly, MSNBC reported. The news came after three reported anthrax cases in Florida, which are now being investigated by the Federal Bureau of Investigation. 
"News about an NBC employee testing positive for anthrax rolled the market over, because if there's a broader terrorist threat, it makes the battle against terrorism a lot closer to home than Afghanistan ( news - web sites ) and it shakes consumer confidence a great deal," said Robert Cohen, head of trading at Credit Suisse First Boston. 
The blue-chip Dow Jones industrial average (.DJI) fell 165.1 points, or 1.75 percent, to 9,245.35 and the broader Standard & Poor's 500 Index (.SPX) slid 18.21 points, or 1.66 percent, to 1,079.22. The technology-laced Nasdaq Composite Index (.IXIC) shed 35.35 points, or 2.08 percent, to 1,666.12. 
U.S. law enforcement officials in the United States were put on the highest alert after the FBI ( news - web sites ) said Thursday afternoon it had received information there could be more attacks in the next few days both at home and against U.S. interests abroad. 
ADVERTISEMENT