Officials say a remotely operated underwater vehicle is getting a close-up look at electric cables that were damaged by what Michigan's attorney general has called a tugboat anchor strike in a channel connecting Lake Huron and Lake Michigan.
Agencies led by the U.S. Coast Guard say the vehicle was deployed Sunday to get visual imagery of the cables at the bottom of the Straits of Mackinac.
Spokeswoman Ensign Pamela Manns said the work was continuing Monday. No details about findings are available.
About 600 gallons (2,270 liters) of insulation fluid leaked after the cables were damaged April 1.
Enbridge Inc. also has used an underwater vehicle to examine nearby twin oil pipes believed to have been dented in the incident.
A spokesman said Monday the company is analyzing video from the inspection.