6. The sickness came in waves
The Spanish flu arrived in the United States in a series of waves, the first in the late winter and spring in 1918, the second in the late summer of that year, and the third wave in January, 1919. For most American cities and communities the worst wave was the second. Not so San Francisco. When the third wave hit the city its business leaders cited the government’s claims that masks had prevented the virus from spreading during the preceding event. Government and health care officials claimed the masks were 99% effective during the second wave. Business leaders argued against social distancing, and kept businesses and schools open during the crucial early days of the third wave. The result was devastating.
The third wave experienced by San Francisco erased the successes it achieved in combating the earlier attacks of Spanish flu. By the time it ended, the loss of life in the city had reached the levels of the hardest hit eastern cities. For the rest of the country, the third wave was comparatively light, with most areas reacting in accordance with the lessons learned during previous attacks. At the time of the Spanish flu attacks in the late summer and the ensuing winter, shortages of medical personnel caused by the war coupled with the false belief in the effectiveness of available masks. Driven by the desire of businesses to remain open, the third wave for San Francisco was the worst of the three.