I am at a loss here, in several senses of the word. It’s my understanding (which may be incorrect) that this fence is a shared resource, but the likelihood that I’ll pry anything out of the apartment owner is pretty low.
And once again I am wrong: some time today he dispatched a maintenance type (I assume) to attempt to repair the damaged section. The tenuous connections to the posts are now less so, and a reinforcement has been added to the lower crossbar.
It’s not very pretty, I suppose, but it’s solid, and it’s better than I had any reason to expect. I will dispatch a letter tomorrow thanking the owner for his attention to this matter.