there's another staircase that goes up to the 1st floor classroom- sorry for the crappy photos, the building is being renovated. the one that goes down has the mini-roof (correctly depicted), the missing one is open.
-------------REVISIONS 2:
can this be tweaked so it doesn't look like the 2 stairwells are in each other's way? the top stair of the basement stairwell is not behind the other stairs, it's to the side (they do not overlap at all on the N/S axis)