U.S. Air Force Tech. Sgt. Logan McFarland, emergency management craftsman, 139th Civil Engineer Squadron, Missouri Air National Guard, instructs a chemical, biological, radiological, and nuclear defense (CBRN) class to Airmen of the 139th Airlift Wing at Rosecrans Air National Guard Base, Missouri, on Nov. 2, 2019. CBRN defense is utilized during situations in which warfare hazards may be present. (U.S. Air National Guard video by Senior Airman Andrew Rivera)