The two were fixing the underground pipeline when fumes apparently escaped, igniting the blaze Wednesday in Clearbrook, about 215 miles (346 kilometers) northwest of Minneapolis, said Kristine Chapin, a spokeswoman for the Minnesota Department of Public Safety. Nearby residents were evacuated because of the thick black smoke in the sparsely populated area.
The U.S. government said it is prepared to tap emergency crude-oil stockpiles to mitigate the effects of the pipeline disruption.
"It looks like it's out now. They're just mopping up and making sure," Blake Olson, a pipeline terminal supervisor, said Thursday morning.
Enbridge Energy Inc.'s 34-inch (86-centimeter) pipeline carries crude oil from Saskatchewan to the Chicago area, Chapin said. The pipe had leaked a few weeks ago and was being repaired, she said.
"It appears as though one of those fittings may have failed and caused fumes to leak, and it caught fire," Chapin said. She said there wasn't an explosion and described it as a "big fire."
The crude is used to make several kinds of fuel, such as gasoline and home heating oil. An average of 1.5 million barrels of oil passes through the pipeline every day, said Larry Springer, a spokesman for Houston-based Enbridge.
The U.S. consumes 20.58 million barrels of oil a day.
The pipeline that leaked and three others were shut down, Enbridge said. Two of the lines were re-started Thursday morning, Springer said. Another line will be inspected to see if it is safe to come back online, but the line with the leak will likely be out for some time, Springer said.
"Nothing is going to be re-started until we're absolutely sure it's safe to be operated," Springer said.
The names of the workers killed were not immediately released.
The head of the Russian Finance Ministry, Anton Siluanov, said that the Americans would suffer additional losses if they impose sanctions on Russia's public debt