BETHEL, Alaska — Authorities say a plane crash that killed two people last December in Alaska is now believed to have been a suicide.

KYUK-AM reported ( ) Wednesday that Mark and Cecilia Matter were in their red plane when it crashed into Marvel Dome, a mountain near the family’s mine.

The National Transportation Safety Board states it could not find any mechanical issues with the Matters’ plane, though. A report by the board concludes that Mark Matter might have crashed the plane intentionally.

The Matters’ children had previously said that Cecilia Matter had cancer and didn’t have long to live.

The Matters’ children declined requests for further comment.

Information from: KYUK-AM,