SAN FRANCISCO -- Members of Coast Guard Sector San Francisco responded to a vessel that sank at its berthing Monday, Aug. 17, 2009. The vessel, USS Wenonah, was a historic tug maintained by volunteer Merchant Marine officers, which sank and released oil into the surrounding area at Pier I on Treasure Island, San Francisco. 090817-G-0000X (Coast Guard video by Seaman Adam Stanton)