The Lake-Dan Ryan train was stopped. It was a Tuesday evening, 5:15 PM, deep in the commuter rush. The temperature was eleven degrees Fahrenheit. Above Wabash Avenue, in the shadow of the Loop’s elevated tracks, the Ravenswood train approached from behind. Its motorman, Stephen A. Martin, would later report seeing a green signal. The train did not slow.
The impact was not a simple crash. The lead train’s rear car was an old, wooden-framed ‘4000-series’ model. The following train’s front car was a newer, all-steel ‘2200-series’. The newer, heavier car telescoped into the lighter one, compressing it to a third of its length. The effect was that of a brutal, metallic accordion. The force derailed both trains, twisting steel and shattering glass onto the street below.
Most disasters have a singular, monstrous cause. This one was a cascade of smaller failures. A failed automatic train-stop system. A possibly ambiguous signal. The brittle cold, which may have affected equipment. The vulnerability of the older car design. It was the worst accident in the CTA’s history, yet it remains obscure outside Chicago. It exists in the archive as a grim engineering lesson, a reminder that systemic safety is only as strong as its weakest, oldest, or coldest component, especially when moving thousands of people through a frozen sky.