TOWER, Minn. (AP) — With an underground fire contained, a three-person crew has entered the Soudan Mine and turned on underground water pumps.

Workers have been battling a fire in Soudan Underground Mine State Park since it started Thursday. Minnesota Interagency Fire Center spokesman Carson Berglund says the fire was greatly subdued Sunday, but not completely out.

Workers entered the mine Sunday, restored electricity and turned on pumps that work to remove water that seeps into the mine from the ground above.

Minnesota Department of Natural Resources spokesman Mark Wurdeman says workers also determined there was likely no water damage to the $100 million University of Minnesota research lab in the mine. Workers determined the fire burned mostly wood material cast off over the years. The fire’s cause is unknown.