"If you see something, say something," the ubiquitous anti-terror ads in New York City read—and a Times Square T-shirt vendor did exactly that on Saturday night, thwarting a potential terrorist attack. After alerting two police officers to a smoking Nissan SUV on 45th Street and Broadway, NYPD cleared the area and discovered what appeared to be a car bomb consisting of propane tanks, jugs of gasoline, gunpowder, electronic components, and a clock. Cops reported seeing a man running from the scene as they approached the car. "We are very lucky," Mayor Bloomberg said at a press conference after 2 a.m., still wearing his tuxedo from the White House Correspondents' Dinner. "Thanks to alert New Yorkers and professional police officers we avoided what could have been a very deadly event." Police are working on uncovering a motive for the attempted attack. The car in question appeared to be stolen and had a Connecticut license plate from another vehicle.