In 1989, Crowley tugs were first on the scene of the crippled tanker "Exxon Valdez" in Prince William Sound, Alaska. The "Exxon Valdez" oil spill was the second largest in U.S. history (after "Deepwater Horizon", 2010) and Crowley was the prime supplier of marine equipment and personnel for the cleanup. To try to avoid future disasters, the Alyeska Pipeline Service Company contracted with Crowley to provide tanker assistance and escort work in Valdez and Prince William Sound using tugs with “best available technology.”