The Coast Guard and the state Department of Environmental Protection were investigating Sunday why a 70-foot barge and a tugboat sank in New Haven harbor.

Petty Officer First Class John Olsen of the Coast Guard said the boats sank late Saturday or early Sunday in the northern part of the harbor. No one was aboard either vessel.

Olsen said there was minor contamination in the harbor from fuel that leaked out of the tugboat and a 30-ton crane that was on the barge. He said the barge was not carrying any hazardous materials.

Authorities planned to raise the boats as early as Monday, and then they will try to determine what happened.

Olsen said the barge may have taken on water for some reason and pulled the tug down with it. The two boats were tied together. They sank at their moorings and were not blocking the channel.

The barge and crane were being used for work on the Tomlinson bridge in New Haven.

–Associated Press