Can I remove dividing wall
 

I have a 1950's home. They added an extension at one point, but in the basement they left the concrete dividing wall in place so you can't actually get to the other side of the basement(below the new addition) unless you crawl through a large window that must have been the outside window of the original home. Is it safe to me to remove enough blocks(2 or 3 per level) so that a person can at least walk from one side to the next? I don't see how the concrete blocks under the window openeing actually support anything, so I was hopeing to remove some. Any thoughts? Or who can I call about such things? I've attached a couple images.

You should be able to. Just do not remove any more then you have to, to make the opening down to the Slab.