Washington, D.C., circa 1919. “Walter Reed Hospital flu ward.” One of the very few images in Washington-area photo archives documenting the influenza contagion of 1918-1919, which killed over 500,000 Americans and tens of millions around the globe. Harris & Ewing glass negative.
The flushing of streets and sewers by sprinkler trucks was a widespread if not terribly effective public-health measure during the “Spanish influenza” epidemic of the late teens. LOC
San Francisco circa 1919. “Nash Two-Ton Tanker Truck.” This begins a new series of photos, scanned by Shorpy from large-format negatives taken by or for Christopher Helin, travel and automotive editor of the San Francisco Examiner from about 1915 to 1930.
The mortality rate among adults in the prime of life was so high that many parents of young children died.
November 24, 1925. Washington, D.C. “City orphans at Ambassador Theatre.” LOC
http://www.history.com/topics/1918-flu-pandemic source for number of deaths