phal in S/H old roots rotting

[murphy48]

Three weeks ago I put a new phal in S/H. It had active root growth. I just pulled it out as all the flowers were wilting. All the older roots are a squishy mess. The ends where it was growing still seem firm. What should I do at this point? There are not many healthy areas of the roots left. The tips that are still healthy are far down on roots where the top parts are almost completely rotten...