Oil company BP says ice plugs in a pipeline caused a rupture that spilled 46,000 gallons of crude and water in an oil field on Alaska's North Slope.
BP spokesman Steve Rinehart says the plugs caused pressure to build up in the line on Nov. 29 and then split it. Oil and water sprayed out of a 2-foot lengthwise crack along the bottom of the pipe.
He says the pipeline had been taken out of service several weeks ago because of restricted flow, so it's not affecting production at Prudhoe Bay.
Rinehart says ice plugs occasionally form in pipelines and end up causing a rupture.
He says BP is considering several ways of dealing with the plugs, including applying heat or introducing deicer and warm crude.