MACKINAW CITY, Mich. (AP) — The company that owns twin oil pipelines beneath the waterway that connects Lake Huron and Lake Michigan is preparing to launch an underwater vehicle to inspect damage that may have been caused by a ship’s anchor.

A spokesman for Enbridge Inc. said Monday the remote-controlled vehicle will examine the submerged pipes in the Straits of Mackinac. They are part of Line 5, which carries 23 million gallons (87 million liters) of crude oil daily between Superior, Wisconsin, and Sarnia, Ontario.

Enbridge temporarily shut down the line over the weekend, blaming a power outage at its Superior terminal.

Officials say dents in both pipes may have been caused by “vessel activity” also believed responsible for damaging two electric cables that leaked 600 gallons (2,271 liters) of coolant fluid into the straits.