Because of the complexity of emergency procedures, the stressful situations during which they're executed, the emergency plan must be meticulously designed so that safety managers can quickly find needed information. Regardless of the complex procedures it describes and the trying situations where it would be used, the plan's success is always measured by how effective the evacuation is. Thus, safety-conscious organizations continually try to improve their emergency procedures and the way they present them in the emergency plan. Integrating incoming information during an emergency and correlating this information with the plan's procedures is a manual task for many safety managers. The danger is that the emergency plan can quickly become a bottleneck during the very emergency for which it describes procedures to resolve it. We've faced this problem in the context of improving and optimizing the plain-text emergency plan for the subway system of Valencia, Spain, a mid-sized city. In 1998, the Metro Valencia Safety Office began developing a system to improve its emergency plan. The Hypermedia Emergency Plan has been operational since June 2000 at the Metro Valencia's Traffic Control Office. Our solution was to turn the emergency plan into a multimedia software system that integrates text, audio, video, 3D models, and animations for handling emergencies in underground metropolitan transportation. From our experience with the Hypermedia Emergency Plan, and with the advent of many new technologies (such as mobile computing, wireless networks, Web services, and digital libraries), we're convinced that the time has come to tackle this challenge.