PROVIDENCE, R.I. (AP) — Rhode Island officials are investigating after a barge carrying a crane sank in the Providence River.

The Providence Fire Department responded to reports of the barge sinking around 4:30 p.m. Monday. The vessel had sunk to the river bottom by 6 p.m.

Both the Coast Guard and the Department of Environmental Management were called to the scene over concerns that the barge was leaking fuel.

Officials later determined the sheen in the water was caused by products on the vessel's surface.

The cause of the sinking is still unknown. The owner of the private barge was unavailable for comment.