Index case of COVID-19 was first identified on March 1st, 2020 in the skilled nursing facility in King County Washington. After the first identified index case, symptoms were assessed rigorously for two weeks. Among the assessed residents of 76, 23 people tested positive and 13 of them were asymptomatic at first. A week later, 10 out of the 13 asymptomatic positive patients developed symptoms. In the end, only 3 people remained asymptomatic throughout this process. This article emphasizes testing and surveillance systems based on other methods, not just reliant on symptoms.