Story highlights

It crashed late Wednesday night south of Newberg

The cause is unknown

CNN  — 

A helicopter crashed in a rural field in Oregon, killing both people aboard and starting a land fire, authorities said early Thursday.

The crash occurred late Wednesday night south of Newberg, according to the Yamhill County Sheriff’s Office.

When emergency crews arrived at the scene, they extinguished the fire and found the two victims. Their identities have not been released pending notification of next-of-kin.

“They are believed to be the only passengers in the aircraft,” the sheriff’s office said. “The cause of the crash is unknown at this time.”

Officials from the Federal Aviation Administration and the National Transportation Safety Board will start investigations Thursday.

The helicopter was a Schweizer 269C.