'Something' hit Bison pipeline in Wyoming

Calgary pipeline company TransCanada said it found mechanical damage on its ruptured Bison natural gas pipeline running through Wyoming.

Bison Pipeline LLC, a subsidiary of Canadian pipeline company TransCanada, declared a force majeure last week after discovering a rupture on the network. The Bison pipeline was carrying about 365 million cubic feet of natural gas per day when the rupture was reported.

James Millar, a spokesman for TransCanada, told the Casper (Wyo.) Star-Tribune that investigators found evidence of mechanical damage on the pipeline.

Something hit it, he was quoted as saying. We don't know when, we don't know what, so we're continuing analysis on that as you would expect.

TransCanada officials said they expect to finish repairs to the pipeline this week and then has to wait for federal regulators to approve a restart.

The newspaper said the explosion on the pipeline was heard 30 miles away and a 60-foot section of pipe was ripped apart by the rupture.

Usually we don't get something this early that you get an indication what occurred, said Millar. On this one they were able to see from visual inspections that gave them a pretty good indication of what would have caused the break.