I should have paid closer attention. The first sign was the tips at the center of some of the aloe rosettes started to darken and shrivel. But new leaves emerged from underneath. So my worry level subsided.
But leaves started drying up at the base, and more started decaying at the center. Then a gentle tug would completely remove a cluster, exposing the rot underneath.
I needed to have taken action sooner, but instead I lost almost all of the rosettes on my Short Leaved Aloe (Aloe brevifolia).
Apparently, the soil was retaining water. Perhaps the screen I had placed over the drainage hole had gotten plugged. Perhaps the Aloe was not receiving enough sunshine to dry it out. Perhaps the clay pot, which has thicker than normal sides, was insulating the plant so well that our recent heat wasn't drying it out. But the most likely culprit was me watering the plant too much.
It was difficult to actually touch the soil to verify dryness as the thick, tight leaves of the plant filled the pot. Though it was only lightly watered every 1-2 weeks, it was obviously more than it needed.
Fortunately I was able to find at least one stem that seemed to still be hardy. Will need to let it dry some before I attempt to re-pot. Hopefully, given time (and less water), it will return.
Planted in Pots:
Aloe arborescens 'Variegata': A "Gotta Get" find at the Austin Cactus & Succulent Show; will try to post some additional pictures of this beautiful specimen later.