This video explains how COVID-19 can spread in a community using an example featured in an April 2020 CDC MMWR.
Investigation of COVID-19 cases in Chicago identified a cluster of 16 confirmed or probably cases, including three deaths, likely resulting from one introduction. Extended family gatherings, including a funeral and birthday party, likely facilitated transmission of SARS-CoV-2 in this cluster.
This article was released by the Centers for Disease Control and Prevention.