Universitat Oberta de Catalunya: Crisis Management through Twitter: The Case of the Barcelona Attacks. “This article explores how the Government of Catalonia managed the emergency scenario during terrorists attacks of August 2017 (from 17th to 22nd ) in Barcelona. Twitter was used for public services, Mossos d’Esquadra (the police force of Catalonia) and the Government of Catalonia Civil Defence, as an essential tool to broadcast information, secure people’s security and drive the investigation. We gathered the network of Twitter posts and interactions, with tens of thousands of users, who helped spreading the information, and applied a social network analysis (SNA) methodology to conclude how those users contribute on the crisis management. In this investigation, we have focused on two questions: How does information diffusion spread during this crisis? And who are the actors that contribute to the expansion? This article aims to inform and explore how public services can use social media to handle crisis of any kind, taking advantage of citizens for spreading information that could contribute to a safer and quicker crisis resolution.” The article is a PDF and is in English.