The grounding of the oil tanker "Exxon Valdez" in Prince William Sound on March 24, 1989, produced extensive contamination of the Katmai coastline. By early April, oil had reached Kenai Fjords National Park. Oil reached Cape Douglas in Katmai on April 26 and points southwards in the following week. In early May, a variety of dredges and skimmer vessels were working in the Shelikof Strait, but 90% of the Katmai coastline was oiled. The worst-hit areas were Cape Chiniak and Chiniak Lagoon, Hallo Bay Beach and its lagoon, Cape Gull and Kaflia Bay, and Cape Douglas. Casualties in birds alone were estimated at 8,400 dead birds. Work resumed in 1990, with smaller efforts in 1991 to catch the last oil.