I think it is reasonably clear this was a reference to the Iroquois Theatre fire where 602 people died.
Not at all. The actual quote is The most stringent protection of free speech would not protect a man falsely shouting fire in a theatre and causing a panic. The Iroquois fire was unfortunately all too real.As soon as the US entered WW I the first amendment basically went out the window with the Espionage Act. Schenck was part of that.
R's, John
