Critical incidents (CIs) are sudden, unexpected events that have a significant impact upon children and young people. In response to the Manchester Arena bombing in May 2017, the Association of Regional Educational Psychology Services (EPSs) created face-to-face training materials to support schools with CI response. In order to embed the legacy of this cross-service training initiative, the aim of this research was to explore how these materials could be developed into an online resource through a process of action research. Supported by an IT expert, one trainee educational psychologist (TEP) and five EPs from different EPSs across the region formed a 'task-and-finish' group and followed a seven-phase process, including a pre- and post-phase. 'The Critical Incident Resource' (TCIR) website was created, to support EPs in their support for school CI response. The online resource development highlighted key project management skills for EPs including conceptual, human, negotiation and technical abilities.