Terror alert in New York City

New York City police officers stand guard outside New York Pennsylvania Station on Friday, Sept. 9, 2011 in New York. The city is deploying additional resources and taking other security steps in response to a potential terror threat before the 10th anniversary of the Sept. 11 attacks. U.S. counterterrorism officials are chasing a credible but unconfirmed al-Qaida threat to use a car bomb on bridges or tunnels in New York or Washington. (AP Photo/Jin Lee) <span class=meta>(AP Photo/ Jin Lee)</span>
September 10, 2011 6:46:15 PM PDT