The COSCO Busan oil spill occurred at 08:30 UTC-8 on 7 November 2007 between San Francisco and Oakland, California, in which 53,500 USgal (203,000 l) of IFO-380 heavy fuel oil, sometimes referred to as "bunker fuel", spilled into San Francisco Bay after the container ship M/V COSCO Busan operated by, Fleet Management Ltd., struck Delta Tower of the San Francisco – Oakland Bay Bridge in thick fog.
Investigators found that maritime pilot John Cota was impaired from his use of prescription pharmaceuticals while piloting the boat, which rendered him unable to use the onboard radar and electronic maps correctly, and that the Vessel Traffic Service of the United States Coast Guard failed to warn Cota that the vessel was headed for the bridge. Cota was sentenced to 10 months in federal prison for his role in the incident.
California Governor Arnold Schwarzenegger declared a state of emergency after meeting federal, state and local officials overseeing the cleanup. The proclamation made additional state personnel, funding and equipment available to assess and clean up the environmental damage.