News release

Broken railcar coupler component led to 2024 derailment near Saumon Station, Quebec

Dorval, Quebec,  — 

The Transportation Safety Board of Canada (TSB) released its investigation report (R24Q0089) into the derailment of an iron ore train near Saumon Station, Quebec.

On November 3, 2024, a Quebec North Shore and Labrador Railway (QNS&L) freight train was travelling south toward Sept-Îles, Quebec, on the Wacouna Subdivision when seven cars derailed on the main track near Saumon Station. About 250 feet of track was damaged. There were no injuries and no environmental damage.

The investigation determined that the train separated into two sections after the yoke, a part of the coupler assembly, on the second car failed. Following the separation, the two sections of the train collided, causing the east rail to roll over, leading to the subsequent derailment. 

Post-occurrence examination found that the yoke had internal porosity in a high-stress area. This porosity was not detected during manufacturing, as the Association of American Railroads (AAR) does not require non‑destructive testing for couplers. The in-train forces before the failure were found to be within AAR specifications.

See the investigation page for more information.


The TSB is an independent agency that investigates air, marine, pipeline, and rail transportation occurrences. Its sole aim is the advancement of transportation safety. It is not the function of the Board to assign fault or determine civil or criminal liability.

For more information, contact:
Transportation Safety Board of Canada
Media Relations
Telephone: 819-360-4376
Email: media@tsb.gc.ca