Social Media is responsible for the massive viral spread of people believing in conspiracy theories, antivaxxers, flat-earthers, anti climate-changers, etc. so social media is responsible (indirectly) for people dying due to not being vaccinated.
Social Media is responsible for the escalation in political rhetoric and the gradual ratcheting of tensions in America and the development of the "alt right" and also indirectly responsible for the increase in mass shootings in America due to the propaganda and "fake news" spread on Facebook and Twitter.