Investigation Findings
Why the Canadian National (CN) Railway's freight train failed to stop was unclear. A wrong-side signal problem was eliminated, leaving human error as the only possible cause. However, since the head-end crew of the freight train did not survive, it was not clear why they had erred. However, enough of their remains were found that testing was able to rule out drugs or alcohol as the cause.

Criticizing the "Railroader Culture"
A commission of inquiry investigated the crash. Justice René P. Foisy, from the Court of Queen's Bench of Alberta, held 56 days of public hearings and received evidence from 150 parties. The inquiry report was published on January 22, 1987. Instead of condemning any 1 individual, it instead condemned what Foisy described as a "railroader culture" that prized loyalty and productivity at the expense of safety.

As an example of this disregard of safety, it was noted that the crew of that train had boarded the locomotive at Edson "on the fly." While the locomotive was moving slowly through the yard, the new crew would jump on and the previous crew would jump off. While this method of changing crews saved time and fuel, it was a flagrant violation of safety regulations requiring a stationary brake test after a crew change. Management claimed to be unaware of this practice, even though it was quite common.