Drydock and Tug Sink at Vigor's Everett, WA Shipyard [INCIDENT PHOTO]

A drydock housing the 140-foot Crowley tug Invader sank over the weekend at the Vigor Marine Shipyard in Everett, Wash., bringing the tug and an estimated 50k-60k gallons of diesel with it.

The Coast Guard and Washington Department of Ecology, along with salvage crews, responded to the potential environmental hazard, saying that a light sheen of oil could be seen around the sunken dry dock and vessel and adding that boom has been deployed around the wreck.

According to the Coast Guard statement, the 200-foot section of dry dock began slowly sinking Saturday night and stopped only after making contact with the sea floor at appromixately 12 p.m. Sunday.

At this time both the dry dock and Invader are partially submerged, with the tug resting on its starboard side. The USCG has confirmed with Crowley that an estimated 50,000-60,000 gallons of diesel is contained in the Invader’s fuel tanks. Meanwhile, salvage company was on scene yesterday conducting assessment dives and the plugging the tugs vents.

The Invader is part of Crowley’s Invader-class, a series of powerful, sleek and highly-praised tugs built between 1974 and 1977.