Further study indicated that this large layer was associated with the collapse and abandonment of the Republican house.

Linear layer of cobble-sized and larger unworked chunks of tufo and basalt mixed with large fragments of tile and some pottery. One possible worked tufo block on south end. Located in the southeast corner of the house in Area A. May be the fill of a foundation trench for a wall or a south extension of wall SU420, but there is no visible cut. May be the same feature as SU573, which had a similar composition and alignment. Also similar to SU574 and SU575 on the west side of the house. Underneath the south half of SU572 is a layer with many smaller fragments of tufo and basalt that expands to the east and west.