A helicopter on a wildfire mission crashed in the Payette National Forest, killing the pilot and all three forest workers aboard, authorities said.

A firefighting team found the wreckage late Sunday afternoon, about a half hour after the helicopter went down on a forest road 100 miles northeast of Boise, forest spokesman Boyd Hartwig said.

A fire engine crew was called to put out a small fire amid the wreckage, but all four people aboard the helicopter were dead, Hartwig said. He declined to release further details.

The cause of the crash of the A-Star helicopter was under investigation.

Fire crews have been working in the Payette National Forest to protect the cabin community of Yellow Pine from an 11-square-mile complex of fires. Bands of dry lightning sparked dozens of timber fires in the area over the past week and firefighters from other regions have been sent to help out.