[3] On September 19 Global News described the train's cargo in greater detail, stating it included gasoline, liquid propane gas and butane.

By September 20 several news sources reported a safety investigator attributed the derailment to the work of beavers.

[5][6] April 23, 2020 the Transportation Safety Board of Canada released report R18W0237 which clarified much in the newspapers that had been contradictory or confusing.

It found that:[7] In spring 2017 severe flooding resulted in washouts and serious track damage between Gillam and Churchill, shutting down that portion of the rail line.

This heavy rainfall contributed to water accumulating immediately east of and adjacent to the rail roadbed at the derailment site.

Hudson Bay Railway engineers had been monitoring the high water levels in the area of the washout for weeks preceding the derailment and the last inspection had occurred two days before the incident.

The railway's emergency response plan for a derailment only included providing a reporting structure and a general safety message.

[note 2] This was a remote section of track where the only contact between train crews and the rail traffic controller was by radio.

The derailment was discovered by accident when a helicopter pilot flew nearby to pick up some surveyors who actually heard the event.