NEW YORK — New York City police were questioning people and studying video surveillance tapes Thursday to determine who may be responsible for detonating two makeshift grenades outside the building that houses the British Consulate (search) earlier in the morning. The explosions, which occurred on Britain's Election Day, caused the glass panels at the building's entrance in midtown Manhattan to shatter but no one was injured, officials said. A one-foot chunk from the planter was also torn off. The department's bomb squad was at the scene and streets were closed in the area. The blasts happened at 3:50 a.m. EDT....