Dispatched for reported basement fire, 2 story residential structure. Arrived on scene with smoke visible from Side C and through the open front door.  360 of structure revealed visible fire through a basement window and no exterior door to the basement.

Picture 1-living room immediately above the fire room
Picture 2-floor joists
Picture 3-Exterior damage, view of window to the fire room

I thought these photos would be another good example of construction hazards and the need to consider time on scene and fire progression.  With what appeared to be an intact floor in the living room, an experienced crew searching the first floor recognized the hazard (soft floor) and worsening conditions as well as the Division C officer; both notified the IC and evacuated the structure. 

No injuries.