Mafia II baseball glitch?

When I first started playing Mafia II, the game glitched and suddenly I was in a ballpark, surrounded by lots of fans screaming and whistling from the bleachers. I had to restart the game. I have since completed it and there was never any mission to a baseball park. But, the ball park shows up on the map (in Kingston) and if you walk around it you can hear fans screaming. There is no way in though. I can only guess that this was intended as part of the game and was never completed? Unless I'm missing something...?