The final collapse of Jerusalem was a total devastation that wiped out the city's governmental, civilian, and spiritual centers. This act of burning and destruction was carried out during the fifth month by Nebuzaradan [מלבי״ם].
The devastating fires consumed a variety of structures, though there are different understandings of exactly which civilian buildings were targeted. A straightforward reading suggests that the fires swept through the everyday homes of the city's residents [רד״ק, ביאור שטיינזלץ]. A more focused view argues that the destruction was aimed specifically at the estates of the nation's leaders and prominent figures [מצודת דוד]. On the other hand, ancient rabbinic traditions interpret the targets not as private residences, but as public gathering spaces, most notably the synagogues [רש״י, רד״ק, ביאור שטיינזלץ]. Some even suggest that this widespread destruction included the Holy Temple itself [ביאור שטיינזלץ].
Beyond reducing these vital buildings to ash, the Chaldean forces dismantled the city's defenses. They systematically broke apart and demolished the protective walls that once fortified Jerusalem, leaving the city entirely shattered and vulnerable [מצודת ציון, ביאור שטיינזלץ].