BROOKLYN, N.Y. — The cleanup of the Gowanus Canal suffered a setback Tuesday after a barge filled with contaminated material from the bottom of the canal sank to the bottom of the Gowanus Bay.

The U.S. Environmental Protection Agency says a contractor has already pumped water from the sunken barge into an empty one.

Dredging has been suspended so crews can secure the barge.

The EPA is looking into whether contaminated sediment was released into the water and deciding what steps to take next.

The federal government declared the 1.8-mile canal a Superfund site in 2010.