1903: One month after it opened to great fanfare, the Iroquois Theatre in Chicago was gutted by fire. A floodlight ignited drapery during an afternoon performance of Mr. Bluebeard. The fire curtain at the front of the stage was probably not fireproof, and anyway, it got stuck. Theatre staff dithered; the audience panicked; emergency doors jammed. Result: 602 members of the audience died, many of them children. Burned, trampled, suffocated.
Carl Prinzler, a hardware salesman, had a ticket for the show, but cancelled at the last minute. The one benefit to emerge from the disaster was that Prinzler and two colleagues devised a panic-release bar for emergency exit doors.
Source: Joanna Bourke, Fear: A Cultural History (2005), pp. 51–2, 58