VANCOUVER -- The Canada Energy Regulator has fined an Enbridge subsidiary $40,000 for the 2018 pipeline explosion in northern British Columbia, which led to natural gas shortages throughout the province.

The regulator said pipeline operator Westcoast Energy Inc. failed to properly inspect the 90-centimetre pipeline before the Oct. 9 blast, which erupted into a massive fireball that could be seen from kilometres away.

The Transportation Safety Board previously determined the explosion was caused by undetected cracks on the outside surface of the pipeline.

In a news release Thursday, the Canada Energy Regulator said Westcoast Energy Inc. "did not follow its integrity management program for stress corrosion cracking and inspection practices."

Had the Enbridge subsidiary done so, the defect "could have been detected to avoid the rupture," according to the regulator.

The pipeline explosion happened about 13 kilometres north of Prince George, and about 125 people living within a two-kilometre radius of the blast site were forced to evacuate as a result. No one was injured.

The Canada Energy Regulator acknowledged Westcoast has since taken steps to prevent a similar accident from happening.

"This included shortening the in-line inspection interval for its (pipeline) and implementing numerous organization changes to address integrity management practices," the regulator said.

Read the Transportation Safety Board's report on the rupture here.

With files from The Canadian Press