Instead of writing letters to the city which will likely find their way to the trash can once received, I'd suggest leveraging the many, many politicians (local/state/federal) who live within 5 blocks of this location and directly engage them. Neighborhoods such as upper East Falls with a high concentration of resident politicians tend to get issues such as this resolved that much faster - take advantage of this and use it to your favor!

Thank God there were no pedestrians around there at the time.