9/11 Tribute Lights

Hi all,

I plan on going to Brooklyn Bridge Park to shoot the 9/11 tribute lights. On return back I was thinking of going to the location the lights are located, the roof of the Battery Parking Garage. I have seen pictures of people at this location.

My question is: is this an area where they only let certain people go or can anyone head up to see this? any help or insight on this would be appreciated.