$ENB Enbridge's Line 5 pipelines beneath the Straits of Mackinac linking two of the Great Lakes appear to have been damaged by the same vessel believed to have caused a recent leak of 550 gallons of coolant fluid from submerged electric cables.

Michigan Gov. Snyder says ENB notified the state about the damage to its Line 5 pipelines, saying it was minor and consisted of three small dents; ENB says the structural integrity of the pipelines was not compromised, and it is "taking immediate action to assess appropriate, reinforcing repairs."

The 65-year-old pipelines carry 23M gallons/day of crude oil across the Straits of Mackinac, which connect Lake Huron and Lake Michigan.