Abstract: In 2014, the South Korean ferry, Sewŏl, sank. In sinking, it took with it 304 lives, as well as initiated broad public dissent that lasted several years. In this study, we investigate how online social media users employed and manipulated the emotions toward this disaster for political purposes. By the utilization of digital humanities methodologies (i.e., topic modeling and frequencies) on the data collected from selected Facebook accounts, we compared different strategies of online engagement with the intersection between mass death commemoration and political activism. In particular, we explored the delegitimization of President Pak Kŭn-hye, her impeachment, and the resultant elections in 2017. Quantitative and qualitative analysis revealed that different social actors manipulated their audience's emotions through posts on their Facebook walls in a manner that politicized the more personal mournful discourse. These social actors associated the disaster with the president's ineptness, especially after her corruption was revealed in the November 2016 scandal. From that point onward, the online memorialization of the Sewŏl's victims became a weapon in the broader efforts to oust the president and to change the political system.