An active shooter response exercise participant simulates firing a handgun during an active shooter response exercise at Marine Corps Air Station Miramar, California, Sept. 2. The station also participated in an aircraft mishap response exercise the next day as part of required annual safety training for the installation. - An active shooter response exercise participant simulates firing a handgun during an active shooter response exercise at Marine Corps Air Station Miramar, California, Sept. 2. The station also participated in an aircraft mishap response exercise the next day as part of required annual safety training for the installation.