If you step onto that section of sidewalk, you fall off of the map. And you fall a very very very long distance down.
It gets worse. Once you are down there, your game starts to screw up in weird ways. It almost locked up on me completely at one point, and the only way I could get back to the game was to -once I was able to- disconnect and then reconnect. When I fell down there yet again, I was only just able to escape before things really started to get weird again by suiciding.
This is not good. I suggest that this map be removed and repaired, or just removed.