Collapse of brick from wall (17020) - nails found used in construction of the brick superstructure. Artificial trench (dug by MAP in 2018*) separates 17188 and 17182, but these two SUs are equal in color, compaction, and composition. *We briefly opened this quad at the end of 2018, but decided to wait to 2019. As a result, a shallow furrow at the entrance was created by excavators before we stopped work.