Was this an established/mated pair of clowns or did you have 2 that had been in the same tank for just a short period?
If you rearranged the 'scaping, is it possible you had 2 same-sex clowns that had managed a truce and were now fighting with the result being one got killed and the other got herself damaged in the process? Did you ever see them fighting?
If you rearranged the 'scaping, is it possible you had 2 same-sex clowns that had managed a truce and were now fighting with the result being one got killed and the other got herself damaged in the process? Did you ever see them fighting?