In the cultural and religious history of Saint Patrick’s Purgatory—a centuries-old Catholic pilgrim site situated on Station Island within the waters of Donegal’s Lough Derg—the mass drowning of 1795 stands out. The aftermath was devastating, stamping a lasting mark on the memory of place. The disaster continues to be complicated by its entanglement with a contested Catholic and Protestant partisan narrative, and the mode of remembering forges the social identity of religious place. As in tragedies of the post-2013 European Migrant Crisis involving overladen and poorly maintained boats sinking in the waters of the Mediterranean, a web of structure, agency, technology, and environment ensnares the vulnerable.