(CNN)Five people were killed when two small airplanes collided in midair Wednesday over a remote section of Alaska, the Alaska State Troopers reported.
Alaska plane crash: 5 die in midair collision
It's not known why the midair crash happened about 376 miles west of Anchorage, said Allen Kenitzer, with the Federal Aviation Administration office of communications. He said the crash happened under "unknown circumstances."
The collision involved a Hageland Aviation Cessna 208 Caravan carrying three people and a Renfro's Alaska Adventures Piper PA-18 Super Cub with two people inside, said Candis A. Olmstead, director of public affairs for the Alaska National Guard.
An aviation company contacted the Alaska Rescue Coordination Center at 11 a.m. and said they had lost radio contact with an aircraft and that it was overdue, she said.
About 15 minutes later, the Alaska State Troopers contacted the Alaska Rescue Coordination Center to report a second aircraft was overdue, Olmstead said.
Later in the day, an aircraft spotted wreckage of the two planes on the ground near Russian Mission, she said.
Russian Mission is a Yup'ik Eskimo village along the Yukon River, about 376 miles west of Anchorage, according to a website for a school in the area.
The crash occurred in an area of rolling hills and heavy vegetation with an elevation between 600 to 800 feet. Skies were clear and temperatures were around 63 degrees, she said.
An Alaska Army National Guard UH-60 Black Hawk helicopter from the 207th Aviation Battalion, based out of Bethel, left about noon and flew to the scene, Olmstead said.
Names of the people on board have not been released. The FAA and National Transportation Safety Board are investigating.