Exxon Valdez oil-spill. Clean-up operation under way on the rocky coastline of Latouche Island, Alaska, after the world's worst environmental disaster relating to the grounding of an oil tanker. Here, workers use high-pressure hot water hoses and pump machinery to wash, then vacuum, the slick coating these rocks. On March 24, 1989, an oil tanker from Exxon Corporation (USA's largest oil concern) struck Bligh Reef near the Alaskan oil terminal of Valdez. At least 2000 kilometers of shoreline, largely National Reserves, were contaminated having a disastrous effect on wildlife. Some 11, 000 people were involved in the clean-up, at considerable cost to the Exxon Corporation.