Crews are trying to clean up more spilled fuel from Boston Harbor than originally estimated after a small crane barge sank early this morning.
A state Department of Environmental Protection official said about 145 gallons of diesel and hydraulic fuel may have spilled into the water.
The Coast Guard was notified just after 1 a.m. that the 12-foot by 30-foot barge tied up near Charlestown sank.
A DEP emergency spill response unit put out 1,000 feet of floating boom to try to contain the spill.
Boom was also placed around the USS Constitution to protect the historic vessel.
Original estimates put the amount of spilled fuel at about 20 gallons.
Petty Officer Connie Terrell said that crews were using absorbent pads to get the fuel out of the water.
Coast Guard officials were monitoring the clean up, but the owner of the crane barge is responsible for it as well as salvaging the boat.
Terrell said it appeared the barge was moored to a pier and when the tide went out it somehow struck the pier and flipped over.