Efforts to stem the Deepwater Horizon oil spill Efforts to stem the Deepwater Horizon oil spill Efforts to stem the "Deepwater Horizon" oil spill were ongoing from the time that the "Deepwater Horizon" exploded on 4/20/2010 until the well was sealed by a cap on July 15, 2010. Various species of dolphins and other mammals (61 casualties), birds (2,095 casualties), and the endangered sea turtles (467 casualties) have been killed either directly or indirectly by the oil spill. The "Deepwater Horizon" spill has surpassed in volume the 1989 "Exxon Valdez" oil spill as the largest ever to originate in U.S.-controlled waters; it is comparable to the 1979 Ixtoc
Torrey Canyon oil spill and other substances used in an effort to mitigate damage. At the time, it was the world's worst oil spill, and led to significant changes in maritime law and oil spill responses. It remains the worst spill in UK history. When laid down in the United States in 1959, "Torrey Canyon" had a capacity of 60,000 tons; the ship was later enlarged to 120,000 tons in Japan. She was named for a geographical feature in California. At the time of the accident, "Torrey Canyon" was registered in Liberia and owned by Barracuda Tanker Corporation, a subsidiary of Union Oil Company