Your saying there is a crossing to the left and parallel to the ladder one? It seems to me like the island piece prevents from anyone crossing parallel and to the left of the ladder one.

Right the issue is that there are actually (as far as I can tell) 5 buildings within the area and rather than marking the entire area as a building I was going to mark the individual buildings as building=hospital. See building=hospital

I am not experienced though so I will leave it up to you.