Is it possible that the cocciopesto represents the "cleaning up" of the room and intentional dumping of pavement fragments into the tanks, which were partially filled in and out of use at the time of the fire?
Fill of 20049 below collapse material and inerface layer. Perhaps bits of cocciopesto lining that had fallen on top of previous fill (SU 20075) create the concentration of mortar and small tile fragments in this layer. (KG)
SU 20070: view toward N