The board determined that fatigue caused the engineer and conductor on a Union Pacific Railroad train to fail to respond appropriately to wayside signals governing the movement of their train, leading to a fatal collision with another train.
The June 28, 2004, collision derailed four locomotive units and the first 19 cars of the Union Pacific train as well as 17 cars of the BNSF train. As a result of the derailment, the 16th car in the Union Pacific train a tank car loaded with liquefied chlorine was punctured, causing the release of approximately 9,400 gallons of chlorine. The chlorine vaporized and engulfed the area surrounding the accident site.
Three people, the Union Pacific conductor and two local residents died from the effects of chlorine gas inhalation.
Sleep Dept, Disrupted Circadian Rhythms Played Roles
The NTSB's investigation determined that sleep debt, disrupted circadian processes, limited sleep during the weekend preceding the accident and long-duty tours reduced the capacity of Union Pacific's engineer and conductor to remain awake and alert the night of the accident.
The board also noted that the conductor's consumption of alcohol on the evening before the accident likely added to his fatigue.
"Get enough sleep it sounds so simple and yet we continue to see accidents caused by fatigue," NTSB Acting Chairman Mark Rosenker said. "How many more tragedies have to occur before employers and employees get the message that being well-rested is critical to job performance?"
Board Urges Railroads to Use Accident as a Case Study
An examination of the engineer and conductor's off-duty time revealed that neither had obtained adequate rest during their off-duty time. As a result, the board recommended that all railroads and railway organizations use the accident as a case study in fatigue awareness training to illustrate the importance for rail carriers to provide employees opportunities for adequate rest and to make employees understand how important it is to rest in order to perform efficiently on the job.
Further, the board recommended that the Federal Railroad Administration (FRA) require railroads base their crew scheduling on scientific measures designed to reduce fatigue and to limit the railroads' use of limbo time.
A synopsis of the NTSB's report, including the probable cause and recommendations, is available on the Board's Web site. The board's full report will be available on the Web site in several weeks.