The destruction of Jerusalem and the subsequent march into exile were marked by cruel humiliation and forced labor, specifically designed to break the physical strength of the young men [שטיינזלץ].
The primary approach among commentators views this suffering as brutal physical labor. The captors bound the young men and loaded massive millstones onto their shoulders to exhaust them [רש״י, שטיינזלץ]. Because the low-lying land of Babylon lacked suitable stones for milling, Nebuchadnezzar forced the Judean captives to carry these heavy stones all the way from Jerusalem to Babylon [תורה תמימה]. Others suggest a different form of labor, explaining that the youth were not carrying the stones on their backs, but were instead forced to physically turn the flour mills to grind grain for the enemy camp [אבן עזרא, צאינה וראינה]. A completely different interpretation views this grinding not as physical labor, but as a term for sexual abuse. Much like the biblical figure Samson in his captivity, these strong young men were subjected to deep disgrace, forced to impregnate enemy women in order to produce powerful children for their captors [תורה תמימה].
The torment continued until the youth reached a state of complete physical collapse [רש״י]. Commentators offer various explanations for the wood that caused their final breakdown. Some connect it to the milling labor, suggesting the young men collapsed from the sheer effort of pushing the heavy wooden handles of the flour mills [אבן עזרא]. Others propose they were crushed under massive loads of firewood they were forced to carry to supply the enemy camp [אבן עזרא, צאינה וראינה]. Another perspective describes the captives being marched in chains with blocks of wood tied to their legs, dragging them down and causing them to stumble along the journey [שטיינזלץ].
However, some question why mere exhaustion from carrying wood or tripping would be considered a tragedy severe enough to be recorded in this context. Addressing this, a chilling interpretation explains that this was not a matter of stumbling from fatigue at all. Instead, it was a brutal mass execution where roughly three hundred infants and young boys were skewered and crucified together on the branch of a tree [תורה תמימה].