The wreckage of a steamship that sank in the 19th century after a collision in San Francisco Bay with a vessel arriving from Hong Kong has been found near the Golden Gate Bridge.
The City of Chester was discovered encased in mud by researchers using sonar in waters about 65 metres deep.
The 1888 sinking of the passenger steamship, which cost 16 lives, was used to whip up anti-Chinese sentiment at the time.
The bigger ship which hit it, the Oceanic, had sailed from Hong Kong and was carrying Chinese immigrants and a mostly Chinese crew.
"The ship is very much intact," said James Delgado, director of Maritime Heritage at the National Oceanic and Atmospheric Administration (NOAA) and a shipwreck investigator.
A boat equipped with sonar scanners captured the first underwater images of the City of Chester last May.
It took NOAA researchers nine months to review the data and reconstruct images of the ship, which came to rest upright at the edge of a sandbank, the NOAA said in a statement.
High-resolution sonar imagery identified the hull of the ship rising six metres from the sea floor and a large gash on the vessel's left side, NOAA said.
The 61-metre long City of Chester, which was heading up the California coast to the city of Eureka, was nearly cut in half by the 128-metre steamer Oceanic in August 1888.
The collision fuelled a racially charged backlash against the Oceanic's mostly Chinese crew, despite their having rescued most of the City of Chester's 106 passengers, Delgado said.
Newspapers at the time falsely reported that the Chinese crew had ignored drowning white passengers.
NOAA is building a website to tell the story of the City of Chester and is planning a San Francisco exhibit of sonar images and historic photos of the ship later this year. Delgado said the tale of the City of Chester was important because it dealt with timely issues of immigration and racism.