The Commonwealth of Pennsylvania is expanding the knowledge and expertise of its mine rescue teams through innovative training technologies. Full-scale mine rescue simulations, including working in theatrical smoke, have become routine for Pennsylvania mine rescue team members. Now Pennsylvania is transforming its mine rescue training by incorporating computer simulation. These new training programs help to produce mine rescue teams that understand effective emergency response at the mine rescue level and the command centre level. The Pennsylvania Department of Environmental Protection's Bureau of Deep Mine Safety has been working with the NIOSH-Pittsburgh Research Laboratory to develop the Mine Emergency Response Interactive Training Simulation (MERITS). MERITS is an interactive multimedia computer simulation, delivered via Internet, of an emergency at an underground mine. It simulates both the underground and surface activities at the mine site and provides the interactive feedback to inform the user (command center trainees) of those events. As trainees work to resolve their emergency, their decisions affect the progress of the simulated emergency. Twenty-one mine rescue team members participated in MERITS training sessions at the Bureau of Deep Mine Safety Offices in Edensburg, Pennsylvania, in January and February 2001. The team members represented companies from both the coal and stone industries and simulated roles as command center decision-makers. Command center training complements the extensive mine rescue scenario training that Pennsylvania already requires for its mine rescue teams. "MERITS provides a format that is inexpensive, versatile and flexible for training personnel in mine emergency management," Richard E. Strickler, Director of the Bureau of Deep Mine Safety, said. "Although mining disasters and emergencies have declined over the last decade, so has the hands-on experience that our aging workforce is taking with them when they retire from the industry." Pennsylvania's use of the MERITS training program gives miners hands-on command center experience to complement their years of mine rescue knowledge and skill. Miners participating in all-day training sessions are able to incorporate what they have learned from Mine Emergency Response Development (MERD) and Mock Drill scenarios into this interactive computer training. Miners have responded positively to the training sessions. In post-test training evaluations, they described the MERITS training as very realistic and beneficial to their emergency response preparedness. As a result of this training, Pennsylvania mine rescue team members are now more knowledgeable about the activities if emergency command centers and also more aware of how their role as mine rescue team members fits within overall emergency response activities.