Broken rail cause of Clair, Sask. CN freight train derailment

A broken rail was the cause of a Canadian National Railway (CN) freight train derailment in October 2014 that forced the evacuation of Clair, Sask.

In a report released Wednesday, the Transportation Safety Board (TSB) of Canada said the train, heading from Winnipeg to Edmonton, derailed on the morning of Oct. 7, 2014 “when a sudden and catastrophic failure of one of the rails occurred under the train,” causing 26 cars to derail.

Six Class 111 tank cars loaded with dangerous goods, the same tank cars involved in the Lac-Mégantic disaster, were part of the derailment.

READ MORE: Sask. train derailment cars same as those in Lac Megantic disaster

Two of the cars leaked petroleum distillates and when CN emergency responders were flaring the contents of one of the cars, a flash fire occurred when the vapors inside the tank car ignited.

The explosion sent a large fireball towards two emergency responders. They were not injured as they took immediate action to avoid the flash fire.

WATCH BELOW: Wadena Volunteer Fire Department posts video of explosion at the site of a 2014 Saskatchewan train derailment 

In the report, TSB officials said the emergency responders were likely fatigued and did not consider all the risks prior to starting flaring operations.

The agency also found CN did not document the close call or proactively share that information with outside agencies.

“If company and industry guidance is not followed and close-calls during emergency response activities are not properly documented and openly shared among all responding agencies, similar circumstances could occur, putting emergency response personnel at risk” TSB manager and lead investigator, Rob Johnston, said.

WATCH BELOW: Transportation Safety Board of Canada lead investigator Rob Johnston discuss his findings into the derailment

4:03 Catastrophic rail failure cause of CN derailment near Clair, Sask.

TSB said CN has improved flaring procedures since then and enhanced documentation requirements for emergency response activities.

“Two CN emergency responders, both industrial firefighters wearing personal protective equipment, used a fuse to produce a controlled flash fire that burned for two seconds to eliminate flammable vapours and allow clean-up work to safely continue at the scene,” CN spokesperson Patrick Waldron said in a statement, regarding the flaring incident.

“This was conducted in coordination with local fire and regulatory officials, who were on site.”

Waldron added that “CN is committed to running the safest railway in North America and to learning lessons from every incident to improve safety.”

Saskatchewan’s Environment Ministry has also enhanced its procedures to ensure incident commanders have the proper training and site monitoring activities are established in emergencies involving dangerous goods.

Bock added the government has already implemented some of the recommendations made by the board in the aftermath of the incident. One specific example is “getting all of the hazardous materials coordinators training and keeping that training up-to-date and advancing that training even further.”

READ MORE: Evacuation lifted at train derailment site in Sask.

The TSB report also found that the failure of the rail happened due to an undetected defect.

According to the report, poor rail surface conditions masked the presence of the defect, which reduced the effectiveness of both visual and ultrasonic inspections.

TSB said it is the seventh time in the last 10 years it has investigated a rail break due to a pre-existing defect that was not detected by ultrasonic inspections.

Joel Senick contributed to this story