THINK. What was going on in 1918? I'd hardly call a WWI loan drive a "political" celebration. Here's a good summary of how Philly and St. Louis handled the outbreak differently, with very different mortality results.
Perhaps you should THINK. The rally in Philadelphia was not just a war bond drive, but a political rally given by the corrupt city bosses - who were determined to run the event even after being warned.
WWI was not a war we needed to be involved in, and Wilson’s administration DID encourage city and community activism to supposedly keep the masses in line. His administration was the first true implementation of fascism in this country, where neighborhood monitors were employed to report on their wards and look out for “subversive” behavior. Many war protesters and just plain ordinary people were jailed in regular sweeps. Simply not turning out for these political and war drives was grounds for suspicion. This is why so many Philadelphians showed up that day.
Was it worth 12,000 deaths?
For more insight on Wilson’s fascist movement, you should read Goldberg’s “Liberal Fascism”.