On May 25, 2013, at 2:30 a.m. central daylight time, near Chaffee, Missouri, Union Pacific Railroad (UP) freight train 2-ASMAR-25 UP 5668 South collided with BNSF Railway (BNSF) freight train U-KCKHKM0-05T at Rockview Interlocking, where tracks of the two railroads cross. The BNSF train was moving through the interlocking when the UP train struck the 12th car behind the locomotives of the BNSF train. As a result of the collision, 13 cars of the BNSF train derailed. Two locomotives and 11 cars on the UP train also derailed. Diesel fuel spilled from the derailed UP locomotives and caught fire. The engineer and the conductor on the UP train were injured and transported to a local hospital.
The Missouri State Highway M bridge crossed over the Rockview Interlocking, and derailed train cars struck bridge supports and collapsed portions of the bridge. After the bridge collapsed, two motor vehicles struck damaged highway elements. Five occupants of the motor vehicles were transported to a local hospital.
As a result of their variable work schedules both UP crewmembers experienced disruptions to their normal circadian rhythms for several days before the accident, and at the time of the accident experienced fatigue caused by circadian disruption and the requirement to operate the train during the window of circadian low. Prior to the collision, both UP crewmembers failed to comply with four wayside signals because of likely fatigue-induced performance degradation. Obstructive sleep apnea likely contributed to the engineer's fatigue. Damage was estimated to be more than $11 million.
The National Transportation Safety Board determines that the probable cause of the accident was the failure of the Union Pacific Railroad train crewmembers to comply with wayside signals leading into the Rockview Interlocking as a result of their disengagement from their task likely because of fatigue-induced performance degradation. Contributing to the accident was the lack of: (1) a positive train control system, (2) medical screening requirements for employees in safety-sensitive positions for sleep apnea and other sleep disorders, and (3) action by the Federal Railroad Administration to fully implement the fatigue management components required by the Rail Safety Improvement Act of 2008. Likely contributing to the engineer's fatigue was undiagnosed obstructive sleep apnea. Also contributing to the accident was inadequate crew resource management.