ANCHORAGE -

A Hageland Aviation training flight that crashed near Kwethluk on April 8, killing both pilots on board, was flying at approximately 3,400 feet when something went wrong, according to a preliminary report released April 17 by the National Transportation Safety Board.

The skies over Bethel were clear when the plane departed the airport in the Western Alaska hub around 3 p.m., and the sun was shining.

But the NTSB reports that data archived by the Anchorage Air Route Traffic Control Center suggests there was a quick fluctuation in altitude followed by a rapid and steep descent until ground impact.

By the time Alaska State Troopers and the Alaska Army National Guard arrived, the body of the plane was almost completely burned by a fire that sparked after the plane crashed.

The condition of the plane alters what the NTSB will be able to learn about the crash, according to spokesperson Clint Johnson.

The main wreckage was located in heavily-wooded terrain along a river an an elevation of approximately 75 feet above sea level.

42-year-old Derrick Cedars of Bethel and 46-year-old Greggory McGee were dead when the emergency responders were at the scene.

Investigators have not determined the cause of the crash.