1971 San Francisco Bay oil spill

The 1971 San Francisco Bay oil spill occurred when two Standard Oil Company of California tankers, the Arizona Standard and the Oregon Standard, collided on January 18, 1971, in the San Francisco Bay. The resulting 800,000-gallon spill, the largest in Bay Area history, threatened sensitive natural habitats both inside and outside the bay, including the Bolinas Lagoon, and contributed to the growth of activism against pollution, after thousands of Bay Area residents volunteered to clean up beaches and rescue oil-soaked birds.

Source: Wikipedia — 1971 San Francisco Bay oil spill (CC BY-SA 4.0)