A medical emergency involving a pedestrian shut down northbound 27th street between O and Q streets for nearly one hour Monday afternoon.  It was called in to Police just before  3 pm, and involved an injured pedestrian.  As this image from a nearby City Traffic camera indicates, the street was closed just north of “O” Street, and the ambulance also closed off the inside southbound lane of 27th while the victim was helped.  Northbound 27th was re-opened shortly before 4 pm.