California health authorities have traced a COVID-19 cluster to a birthday party attended by a woman who showed up “joking she may have the virus.” Lisa Derderian, a spokeswoman for the city of Pasadena, told the Los Angeles Times that others contracted the novel coronavirus “because of one person’s negligent and selfish behavior” at the crowded bash which occurred after the city’s March 19 stay-at-home order. Health officials using contract tracing located five other people who tested positive and others who had symptoms but did not get tested. Authorities announced the cluster to drive home the point that parties—including Mother’s Day gatherings—are off limits.