SEATTLE -- U.S. Coast Guard and Washington State Department of Ecology crews are the scene of a sunken tug near Terminal 5 in Seattle.

The 30 foot tug, owned by NRC Environmental Services sank around 10 p.m. Saturday when high waves came over the stern of the vessel, the Coast Guard told KIRO 7.

Two people aboard the tug were rescued, but the tug completely sank in the waters off Terminal 5 on Elliott Bay.

Response crews are concerned about the estimated 200 gallons of diesel fuel aboard the sunken tug, KIRO 7 reported.

So far there have been no reports of visible fuel leaks or fuel order, the Coast Guard reported.