If you go to Grove Street Bridge, there is a red marker. If you walk into it, four fat men will spawn and try to beat the crap out of you for your Subway. If at any time you get pissed off about having to defend your Subway, you can eat it by holding Alt+2 at the same time. That will cause you to eat your Subway. Unfortunately, it will give you internal bleeding and you will die within 10 seconds.  Enjoy!