A Union Pacific Railroad (UP) 4-unit locomotive consist was travelling eastbound in an unoccupied, run-away condition, and at an estimated speed of 60 mph, collided with the lead locomotive unit of a departing westbound UP train. The collision occurred at the west end of Centennial Yard, within the city limits of Fort Worth, Texas. The accident occurred at 11:51 p.m., central daylight time, on August 20, 1997.