Published September 12, 2018 in “They either get well or die” | Full size is 432 × 314 pixels

Philadelphia’s Liberty Loan parade on Sept. 28, 1918 triggered one of the worst outbreaks of flu in the country.

Philadelphia's Liberty Loan parade on Sept. 28, 1918 triggered one of the worst outbreaks of flu in the country.

Philadelphia’s Liberty Loan parade on Sept. 28, 1918 triggered one of the worst outbreaks of flu in the country.

Philadelphia’s Liberty Loan parade on Sept. 28, 1918 triggered one of the worst outbreaks of flu in the country.