Ironically the worst environmental disaster in history was an oil spill that doesnt even rank among the top 50 largest oil spills source lovgren yet the exxon valdez oil spill is widely considered to be the most disastrous oil spill in the world in terms of its environmental impact source exxon the 11 million gallons or 257000 barrels of oil that eventually escaped from the tankers hull continue to affect the surrounding area source lovgren as soon as the ship hit bligh . On the night of march 24 1989 the exxon valdez oil tanker ran aground on bligh reef in the pristine waters of alaskas prince william sound the first of what would turn out to be 108 million. Shortly after midnight on march 24 1989 in a tragic accident deeply regretted by the company the exxon valdez supertanker ran aground in alaskas prince william sound despite the efforts undertaken to stabilize the vessel and prevent further spillage of oil more than 250000 barrels of oil were lost in just a short period of time. The exxon valdez oil spill was one such accident that happened 25 years ago on march 24 1989 the exxon valdezoil tanker heading for long beach california from alaska struck prince william sound s reef it spilled 11 million gallons of crude oil into the pristine waters of the gulf of mexico