Self-supporting interior staircase?

[träarne]

I have a custom-built U-shaped staircase from around 1940, built in a house from that time. It looks like a classic staircase where the outer stringer runs along two exterior walls and the last part after the non-load-bearing wall that I am now going to remove.
No matter how I look, I can't see any proper fastening of the staircase to the non-load-bearing wall other than a few nails through the stringer into the wooden wall, so I'm wondering what the practice is, is the construction usually self-supporting??

The picture is poor but might provide some guidance.

 

[smil]

It is probably attached with two screws in each vangstycke into the wall (look under the steps, they usually hide them there) and two screws under the top step, then into the arch edge. A staircase is almost self-supporting.