A tanker plane crashed, killing two people, during a battle against a forest fire that was itself ignited by a crash that claimed two lives, authorities say.

The firefighting Lockheed Neptune P-2V went down Sunday in sight of a command post set up because of the first crash of a single-engine Cessna on Saturday.The first crash ignited a fire in Olympic National Forest that grew to 15 acres, the U.S. Forest Service said. Killed in the accident were David L. Wurscher, 46, of Bremerton, and Tom Eller, 62, of Newman Lake, officials said.

Those killed in the second accident were the pilot, Ralph Glasgow of Honeyville, Utah, and the co-pilot, Steve Bovey of Alamogordo, N.M.