Problem: How some cities 'flattened the curve' during the 1918 flu pandemic, Philadelphia detected its first case of a deadly, fast-spreading strain of influenza on September 17, 1918. The next day, in an attempt to halt the virus' spread, city officials launched a campaign against coughing, spitting, and sneezing in public. Yet 10 days later-despite the prospect of an epidemic at its doorstep-the city hosted a parade that 200,000 people attended.
Flu cases continued to mount until finally, on October 3, schools, churches, theaters, and public gathering spaces were shut down. Just two weeks after the first reported case, there were at least 20,000 more.