Since the onset of the COVID-19 pandemic in late 2019, the world community has responded with ever-evolving measures to reduce the spread of SARS CoV-2, the virus that causes COVID-19 (Coronavirus Disease 2019)1. One particular area of interest is understanding the risk of the in-person classroom setting and if any mitigation efforts are effective in preventing the spread of disease in that setting. In this paper, we present a case study of a US Army Advanced Individual Training (AIT) course/classroom wherein a student was diagnosed with COVID-19, and there was no apparent spread to others in his classroom. We discuss the mitigation efforts put in place that appear to be, in this case, effective in preventive onward spread of the virus. These are social distancing, face coverings/masks, and hygiene practices including hand washing and sanitation of surfaces.