What impact the 2020 COVID-19 lockdown has had on the spread of the virus in Class 1 cities of India is discussed using an interrupted time series model. Four variants of the susceptible–infected–recovered models are used to develop a counterfactual, which are compared with actual data. The analysis reveals that the lockdown has reduced the number of COVID-19 cases by 23.65 million–33.77 million and averted approximately 0.001 million–0.010 million deaths. At the regional level, it has prevented a major health crisis as existing intensive care unit and ventilator facilities for critically ill patients would have been inadequate.
