Last night, I was on the 7:15 New Haven line train out of Grand Central. We pulled into Fordham, and sat there for about 10 minutes with the doors closed. Eventually, they opened the doors and let people on and off. Anybody know what was up? They made a few announcements about it. I couldn't quite make out what the problem was, but it didn't sound like any mechanical difficulties with the doors. At one point, I heard something about delays up ahead, and at another point, something about police activity.