"Tesoro Logistics LP detected anomalies during an inspection of its 20-year-old North Dakota pipeline just days before the line ruptured and spilled 20,600 barrels of oil onto farmland, the company said on Thursday."

"The six-inch pipeline was carrying Bakken oil to the Stampede rail facility outside Columbus, North Dakota, when it ruptured. A farmer harvesting wheat discovered oil spouting from the line on September 29.

A robot, known as a 'smart pig,' detected anomalies during what Tesoro called routine internal inspections of the pipeline September 10 and 11."

Selam Gebrekidan reports for Reuters October 17, 2013. [2]

SEE ALSO:

"North Dakota Officials Might Finally Spill Details About Oil Spill" (Grist) [3]