This chapter examines the social outburst of October 18, 2019, sparked by a modest Metro fare hike in Santiago that escalated into a nationwide wave of protests blending peaceful mobilizations with destructive violence. Initially triggered by high school fare evasions, the unrest quickly evolved into a broader movement reflecting diverse grievances, including frustrations over the cost of living, inadequate public services, and the perceived detachment between political institutions from citizens. The protests symbolically and materially undermined state institutions, leaving the Piñera administration struggling to govern effectively. Without clear demands from protesters in the initial days, the government’s response—marked by curfews, military deployments, and contentious statements—only deepened public distrust. In this vacuum, the opposition, particularly the new left, reframed the protests as a call for systemic change, strategically aligning the movement with critiques of Chile’s neoliberal framework and the 1980 Constitution. Though constitutional reform was not an explicit demand of the protesters, this interpretation provided coherence to an otherwise fragmented mobilization and positioned the opposition as leaders of transformative change. The events of 2019 marked a rupture in Chile’s political trajectory and set the stage for a constitutional process that would last almost three years.