Lamentations 2:5 (ESV)

5 The Lord has become like an enemy; he has swallowed up Israel; he has swallowed up all its palaces; he has laid in ruins its strongholds, and he has multiplied in the daughter of Judah mourning and lamentation.

As the Lord had previously used his strength for his people, he has now used his strength against them. The result is only the sound of mourning and lament, heard everywhere.