ANCHORAGE, Alaska (AP) – Authorities have released the names of the four people killed when a small airplane slammed into a mountain near the Alaska resort town of Girdwood earlier this month.

Alaska State Troopers identified the victims Friday as 31-year-old Charles Weimer, 60-year-old David Osborn, 55-year-old Karl Erickson and 37-year-old Paul Wiley.

All were Girdwood residents except for Wiley, who lived in Superior, Arizona.

The four died Aug. 4 when the plane hit Goat Mountain at about 5,500 feet (about 1,675 meters) during a short sight-seeing flight over the Girdwood valley. The National Transportation Safety Board says the wreckage was largely consumed by a post-crash fire.

A witness told federal investigators he saw the Piper P22-150 airplane “performing aggressive flight maneuvers” shortly before it crashed.

The cause of the crash is under investigation.