A police officer with a bomb-sniffing dog patrols the Times Square subway station, Friday, Sept. 9, 2011, in New York. Just days 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 City or Washington. (Photo by Mary Altaffer/AP Photo)
