On September 21, 2004, about 3:25 a.m., central daylight time, the Alton and Southern Railway Company remote control train YAS313 derailed during switching operations at the east end of the Gateway Hump Yard in East St. Louis, Illinois. The remote control operator was unable to control the speed of the train as it crested the hump. 3 As the train entered track 066, it collided at 9.6 mph with a tank car containing vinyl acetate. During the collision and subsequent derailment, vinyl acetate began to leak from two tank cars and the cargo from both cars caught on fire.
About 140 people from the surrounding neighborhood were evacuated, and work at the hump yard was suspended. The evacuation order was lifted about 6:00 a.m. No injuries were reported. The weather was clear, about 67° Fahrenheit, with light winds from the south-southeast. It was dark at the time of the accident, but the area was well lit with stadium type lighting.