The National Transportation Safety Board (NTSB) now knows what was behind a fatal 2015 train collision near Roswell, New Mexico, but it doesn’t know why. An NTSB investigation has determined that a conductor’s failure to properly line a switch is the probable cause for the April 28 collision of two Southwestern Railroad freight trains. The striking train crew did not perceive the misaligned switch in non-signaled territory and so did not stop the train before reaching it contributed to the collision.
Post-accident toxicological testing on the engineer of the striking train – who died in the incident - identified significant levels of tetrahydrocannabinol. These results, and the presence of rolling papers and pipes in the locomotive cab suggest the engineer smoked marijuana between 30 minutes and five hours before the accident, and, because the engineer had been on duty for almost 10 hours, he likely used marijuana while on duty and likely was under its influence while operating the train. It could not, however, be determined if the THC in the engineer’s system affected his response to the misaligned switch.