Michigan Gov. Gretchen Whitmer took legal action Friday to shut down a pipeline that carries oil beneath a channel linking two of the Great Lakes. Whitmer's office notified Canadian company Enbridge Inc. that it was revoking an easement granted 67 years ago to extend a roughly 4-mile (6.4-kilometer) section of the pipeline through the Straits of Mackinac. The revocation takes effect in 180 days, when the flow of oil must stop.