On February 21, 1996 at about 5:55 a.m., mountain standard time, Southern Pacific Lines freight train 1ASRVM-18 derailed 39 cars and 2 locomotives while descending the Tennessee Pass, a 3.0 percent grade in the Rocky Mountains of Colorado. The train's three-member traincrew consisted of a locomotive engineer, a student locomotive engineer, and a conductor. According to the conductor, the train was being operated by the student engineer. As the train started the mountainous descent it began gaining speed and eventually ran away. The runaway train broke apart three different times, resulting in three separate derailments.