DIORAMA system assists the incident commander in the management of a mass casualty incident. This system is a mobile, scalable tool that can be deployed at a disaster scene to enable an offsite commander to visualize the location and condition of the casualties, the location and condition of available resources, to aid the evacuator on site to retrieve and evacuate the patients accordingly to their triage level. Our experimental results conducted with human subjects in a simulated disaster site show that the DIORAMA system can significantly reduce the evacuation time (up to 43%) when compared to paper based evacuation. This fact attests to the DIORAMA effectiveness in reducing the patients' mortality.