The under slab preparations are taking place.  More fill is added.  Plumbing for the floor drains and sanitation sewer are roughed in.  Conduits for running electrical wiring is also installed.  Everything is compacted again.

Compacting under slab
Final compacting of underslab material
Under slab plumbing
Plumbing rough-in under slab
Concrete Forms
Final Forms in place ready for concrete