That's a bummer ...
If you had posted just the picture without any comments, my guess would have been that the leaves were trimmed by peeling off the rizhome.
I zoomed into the picture and I do not see anything that would look like rot to me. The leaves and stalks look very healthy. Getting all the leaves like that is so unusual, I have never seen that. The damage looks mechanical.
I would pull the rizhome up, not much more damage you can do to it now, and see if it is all soft and rotten and what the roots look like. In a garden, I would start looking for a gopher or something ...