About 5:46 a.m. CST on December 13, 2001, three Union Pacific (UP) freight trains were involved in a collision and derailment on the Jefferson City Subdivision at Pacific, Missouri, about 35 miles southwest of St. Louis. The collision occurred in double main track territory governed by a centralized traffic control signal system. In total 6 locomotives and 74 cars were derailed.
There were two crewmembers on each of the three trains. Two crewmembers were seriously injured, and two received minor injuries. There was a release of 10,000 gallons of diesel fuel and a small fire. Damages were $10 million.
The weather was overcast with misting rain and a temperature of 36° F. It was dark at the time of the collision.