A tractor-trailer truck that struck and damaged a portion of the stone parapet lining the elevated roadway around Grand Central Terminal has sent debris falling onto the sidewalk adjacent to the Pershing Square viaduct at 42nd Street and Park Avenue. This has resulted in vehicular and pedestrian traffic diversions in the immediate vicinity with the viaduct closed to all north- and southbound traffic at this time, and northbound vehicles on Park Avenue being diverted east at 40th Street. Southbound traffic on Park Avenue is being diverted east at 46th Street and 42nd Street is closed between Lexington and Madison Avenues, as well. Additionally, the sidewalk in front of the Terminal and the Park Avenue entrance to the Terminal under the viaduct are closed to pedestrians. Entrances to the Terminal at the corner of Vanderbilt Avenue on the west and adjacent to the Grand Hyatt on the east are open, however.

UPDATE 8/1/12: All roads are now re-opened.