ANCHORAGE, Alaska (AP) – A witness told federal investigators he saw an airplane “performing aggressive flight maneuvers” shortly before it crashed earlier this month, killing all four people on board.

The witness account is included in a National Transportation Safety Board preliminary report on the crash, released Thursday. The report does not include a cause for the Aug. 4 crash near Girdwood, about 35 miles south of Anchorage.

The victims’ names have not been released.

The Piper P22-150 airplane crashed into Goat Mountain at about 5,500 feet (about 1,675 meters), and the wreckage was largely consumed by fire.

A friend of the plane’s owner told NTSB investigators the purpose of the 15 to 20 minute trip was to fly around the resort town. The plane’s owner was identified as one of the victims.