On the 25th of May, 1950, at around 6:30pm, a crowded tram was making its way through the streets of Chicago. As it approached a switch in the track, the driver missed the frantic signals of a worker on the street, and ploughed through the track switch at high speed. Immediately, the tram collided with a fully-loaded tanker truck hauling gasoline. Fuel spilled out and ignited in a giant fireball, beginning one of the most deadly public transit disasters in Chicago’s history.