If you ran in to a lot of backed up traffic downtown early this morning, the Post explains why: D.C. firefighters rescued a construction worker on the ninth floor of an 11-story building at 1999 K Street NW. The worker fractured his right ankle after a fall at about 7:30 a.m., and because the building does not have working elevators, fire crews had to use a construction crane to get the man down to the street and into an ambulance. Police closed 20th Street between K and L streets for about an hour during the rescue operation.