The state Department of Ecology and the U.S. Coast Guard responded Friday evening to a lube oil spill from a ruptured tanker truck that was aboard a vessel at the Port of Tacoma.

The tanker truck was on board the M/V Midnight Sun at the time of the rupture. The truck was struck by another vehicle, causing the rupture. One of the tanker truck’s four compartments, holding about 1,500 gallons of lube oil, emptied to the deck. Most of the oil was contained on the deck, but about 50 gallons is estimated to have spilled to the Blair Waterway.

A private contractor, NRCES, and other cleanup crews worked on the deck and on the water. The spill to water appeared to be controlled with an oil containment boom, and no further oil is believed to have reached the waterway. State and federal responders will return to the site at daylight to reassess the extent of the spill.