According to a report on http://heraldnet.com a 140-foot tugboat reportedly containing up to 60,000 gallons of diesel that capsized at the Vigor Marine Shipyard along the Everett waterfront.
According to the news source, th dry dock began sinking Saturday evening and stopped about noon Sunday after hitting the sea floor, according to a press release from the U.S. Coast Guard.
The dry dock and the tug Invader became partially submerged.