Staff Sgt. Heidi Williams, 47th Civil Engineer Squadron emergency management section NCO in charge, briefs attendees at a chemical, biological, radiological and nuclear training course at Laughlin Air Force Base, Texas, Sept. 12, 2013. During the CBRN course, instructors show attendees how to perform various, potentially life-savings skills, then assess their performance. (U.S. Air Force photo/Senior Airman John D. Partlow)