Volunteer “patients” portraying gunshot victims tested Southwest Washington Medical Center’s ability to respond to a regional mass-casualty incident Thursday.And their “families” added to the stress, as well.The Vancouver hospital was part of the “Big MAC” — Multi-Agency Coordination — emergency exercise drill staged in Wahkiakum and Cowlitz counties.The drill’s scenario started with a domestic violence incident in Cathlamet. It escalated into a series of shooting incidents that culminated in a Longview-Kelso industrial area, said Vancouver Fire Captain Kevin Murray, a spokesman for the regional exercise.A dozen or so of the most critically wounded “victims” were brought to Southwest Washington Medical Center.Volunteers who portrayed the victims arrived at the emergency department with simulated wounds, a training embellishment known as moulage.In another wrinkle, additional volunteers played the roles of family members who were frantic about the conditions of their wounded loved ones. They were pretty disruptive in the waiting room, said Michelle Halfhill, hospital spokeswoman. A hospital chaplain and social workers responded to that element of the emergency.There were some concessions to practicality, said drill manager Grover Laseke, Cowlitz County’s emergency management director. The participants taken to Vancouver were transported to the hospital in a van, rather than in several ambulances.A Coast Guard helicopter was included in the exercise, but didn’t actually drop off a “victim” at Southwest Washington Medical Center. It briefly touched down at the hospital’s helicopter landing pad, then took off.The exercise gave agencies an opportunity to test their emergency plans and see how their communications systems meshed in a coordinated response to a mass-casualty incident.