Bad surprise at the basement stairs

Did you chip out the wall section yourself? - maybe you could describe your approach and what the actual goal of the "operation slipped rotary hammer" would have been. I still lack a bit of an idea of what exactly the result brought about, meaning what mix of dilapidated condition and massively gone-off-the-rails repair attempt.

Did you knock out the wall piece yourself? - maybe you describe your approach and what the actual goal of the "operation slipped hammer drill" would have been. I still lack a bit the idea of what exactly caused the result, i.e., what mix of a dilapidated condition and massively gone wrong repair attempt.

Look, I removed the asphalt, which went up to the first corner of the stairs. From the other corner, a not-so-thick concrete floor began. However, this was relatively easy to chisel out. I did not destroy the concrete underneath the tile; it was already deteriorated before. It only became apparent when I removed the floor all around. You could also see why the tiles had no grip anymore. I didn't break anything; it was already like that.