On July 10, 1986, Union Pacific Railroad (UP) eastbound freight train No. CLSA-09 struck standing UP freight train No. WPX-08, 8 miles west of North Platte, Nebraska. Due to unusually heavy fog, visibility was limited to about 300 to 400 feet. Train No CLSA-09 was traveling about 40 mph as it approached the area where train WPX-08 was stopped. The engineer applied the brakes when the caboose of the standing train became visible, but the train's speed was reduced to only about 32 mph, when the trains collided. Three locomotives and 11 cars from both trains were derailed. The rear brakeman of train WPX-08 was killed and the conductor injured. The engineer and head brakeman of train CLSA-09 were injured when they jumped from the train.
The major safety issues concern factors that permitted the engineer of train CLSA-09 to ignore weather conditions and signal indications, including the adequacy of the signal system, the adequacy of UP's monitoring of its traincrews, the environment in which the engineer was working, and the engineer's experience, training, and judgment.