In the part where the NYPD have evacuated the school, Chester A. Arthur Elementary School, where it shows the janitor/custodian whatever... check the room and makes sure no one is in there. Then it shows the view over by the desk and you can see that there are NO kids behid there. Then the view goes back to the janitor and he closes the door and locks it. Then the same view of the desk that was shown before you can see the kids under the desk. Then the kids popup and play some games.