In the wake of the recent terrorist attack on the United States, there is an ever-increasing need for the defense against weapons of mass destruction. The use of explosive devices in combination with chemical agents could result in a community disaster with multiple traumatic and medical injuries. Military medical personnel may be the first called upon due to their unique training and equipment. Operation Castle Cascade was a large-scale exercise on a military instillation involving the apprehension of hostages and detonation of an explosive device containing dimethyl sulfate. We will provide details on the medical management of 50 patients with simulated chemical and traumatic injuries. Issues relating to on-site chemical identification, triage, decontamination, treatment, casualty collection, and transportation of casualties are addressed in this article.