The Deepwater Horizon oil spill occurred in April 2010 when an offshore drilling rig, operated by Transocean and owned by BP, experienced a blowout. This incident resulted in the release of approximately 4.9 million barrels of crude oil into the Gulf of Mexico over a period of 87 days, making it one of the largest environmental disasters in U.S. history. The spill caused extensive damage to marine and coastal ecosystems, affecting wildlife and local economies dependent on fishing and tourism. Cleanup efforts involved thousands of workers and various techniques, but the long-term environmental impacts are still being studied and addressed.