ANCHORAGE, Alaska (AP) – Investigators say thick wildfire smoke obscured visibility in all directions when a plane crash killed three people on Alaska’s Kenai Peninsula.

The Anchorage Daily News reported Thursday that a National Transportation Safety Board report released Thursday says the smoke came from the Swan Lake Fire.

Officials say the Maule M-6-235 aircraft flew into the side of a mountain on the north side of Tern Lake June 28.

The crash southwest of Anchorage killed 73-year-old pilot Scott Christy and his 73-year-old wife Jean Tam, as well as 29-year-old passenger Suzanne Glass.

The only survivor was 28-year-old passenger Andrea Joy Cooper.

The report says Federal Aviation Administration weather cameras about 7 miles (11 kilometers) southeast of the accident site showed reduced visibility in all directions due to smoke or haze.

Information from: Anchorage Daily News,