About 4,000 residents of southern Manitoba who rely on natural gas furnaces found themselves coping with wind chills of -45 Celcius (-49 Fahrenheit) , after a gas pipeline exploded in the Canadian province early Saturday morning, sending balls of flame hundreds of feet into the sky.

Officials of TransCanada Pipelines – the company behind the controversial Keystone XL pipeline – said the cause of the blast, which occurred early Saturday morning, is still unknown. There were no injuries in the blast.

Repair crews hindered by icy temps

Although only one of two pipelines supplying the gas distribution in the area was affected, both had to be shut down while repairs were made. While the company originally predicted that most of those left without heat would have their service restored within a few days, crews attempting to repair the pipeline over the weekend were hindered by the extreme cold.

Warming centers were established in several communities. Residents were asked to check on neighbors. Some people used portable electric heaters to stay warm.

The pipelines also provided gas to approximately 100,000 customers in the U.S.

Canada’s federal Transportation Safety Board is investigating the explosion, which reportedly left a crater 30 feet in diameter and ten feet deep. Senior investigator Jerry Berriault said the blast appeared to have started on a 30-inch high-pressure gas line.

"World class" safety record

Despite the incident, TransCanada’s executive vice president, Karl Johannson, insisted that his company’s record is “world class” and that that people living near pipelines should not be concerned for their safety. "TransCanada takes this very, very seriously," he said.

Keystone XL pipeline problems

The incident comes on the heels a November report by November report by CBS that the U.S. Pipeline and Hazardous Materials Safety Administration (PHMSA) – the agency responsible for pipeline safety -- notified TransCanada that nearly 50 percent of the welds on the southern section of the Keystone XL pipeline required repairs. Oil recently began flowing through the southern section.

In making a bid for the approval for the pipeline, TransCanada has argued that it would create jobs and help the U.S. become energy independent.

Environmental risk

Financial manager Tom Steyer said the pipeline, which will pump Canadian tar sands’ heavy crude, would result in higher gas prices in the Midwest and only 35 permanent jobs, while creating an enormous environmental risk to farmland, towns and groundwater supplies.

Writing in the Huffington Post, Steyer said the biggest beneficiaries of the Keystone XL pipeline will be companies backed by the Chinese government, who have invested nearly $30 billion dollars in Canadian tar sands development in recent years.

Chinese companies major beneficiaries

“China now holds 100 percent of Nexen, a tar sands and shale gas company, and also has major stakes in McKay River, Dover, Long Lake and other Canadian tar sands projects. And the Keystone XL pipeline would give them easier access to Canada's energy resources, providing more power for China's economy and more carbon pollution for the world.”

Safer than other transportation methods?

However, supporters of the Keystone XL say pipelines are the safest way to transport oil and gas products and have a positive environmental impact because they take hundreds of trucks off the road.