The Amoco Cadiz oil spill took place on 16 March 1978, when the oil tanker Amoco Cadiz, owned by the American petroleum company Amoco, ran aground on Portsall Rocks, 2 km (1.2 mi) from the coast of Brittany, France. The vessel ultimately split in three and sank. The US National Oceanic and Atmospheric Administration (NOAA) estimates that the total oil spill amounted to 220,880 metric tonnes of oil which amounts to over 58 million gallons or 256.2 million litres, making it the largest oil spill of its kind at the time.