Just after midnight on Good Friday 1989, the giant supertanker Exxon Valdez ran aground on Bligh Reef in Alaska's Prince William Sound to create one of the biggest man-made ecological disasters of the 20th century. Eleven million gallons of crude oil gushed from the stricken tanker into the pristine waters of the Sound, killing whales, millions of fish and birds, and thousands of sea otters. The spill had a catastrophic effect on local communities, wiping out their herring fishery and severely depleting the Alaskan salmon industry for years to come.