Game Crashes at specific point

[efct]

This happens on my second visit to Detroit. just after the convention center. when I try to go through the metro station to the other side of Detroit it crashes at the top of the first flight of stairs. Alternatively if I try to take the alley way to the other side of town it crashes whenever i reach the basketball court.

The game has been great up until this point and I have not had any issues in regards to crashes. I use a ATI Radeon HD 5700 video card and have tried EVERYTHING that was posted in the general help threads. I use steam and have also reinstalled, and messed with settings including changing .dll files.

Any help would be appreciated. Thanks!