25 years ago , Exxon Valdez spilled 11 million gallons of oil into Alaska 's Prince William Sound . Marybeth Holleman : Animals , coastal ecosystem damaged Some are still listed today as `` not recovering . '' ; oil still pollutes beaches . She says no matter how we make drilling , tankers , pipelines safe , risk will never be zero . Holleman : The Gulf spill is the worst environmental disaster in U.S. history and it could have been much worse if not for a series of decisions made by BP that led to its own catastrophe.
25 years ago , Exxon Valdez spilled 11 million gallons of oil into Alaska 's Prince William Sound . Marybeth Holleman : Animals , coastal ecosystem damaged ; oil still pollutes beaches . She says no matter how we make drilling , tankers , pipelines safe , risk will never be zero . Holleman : The Gulf spill is the worst environmental disaster in U.S. history and it could have been much worse if not for a series of decisions made by BP that led to its own catastrophe.