On Oct. 4, 1918, City Manager of Health and Charity and former Denver mayor Dr. William H. Sharpley responded to rising influenza cases and deaths by ordering hospitals to isolate flu patients.

Denver residents generally adhered to the health department’s closure order and public gathering ban. However, people congregated outdoors in the busy downtown shopping district, as the public health edicts only applied to indoor assemblies. Clergy began holding outdoor services for their congregations.

By Oct. 15, physicians reported 257 new cases in the last 24-hour period, bringing the total number of cases since the start of the epidemic to 1,440.