ANCHORAGE, Alaska (AP/KDVR) — Gregory Harms, 52, has been identified as the Colorado man killed in a deadly helicopter crash north of Anchorage Saturday evening that left only one survivor.

According to officials, the helicopter, which was chartered for a heli-skiing excursion, crashed into a mountain near Knik Glacier before rolling nearly 900 feet downhill, killing the pilot and four of the five passengers on board.

The four other people killed were identified as Petr Kellner and Benjamin Larochaix, both of the Czech Republic, as well as Sean McManamy and the pilot, Zachary Russel, who were both Alaska residents.

The sole survivor is in serious condition according to a spokesman at Providence Alaska Medical Center in Anchorage.

Mary Ann Pruitt, a company spokesperson for the Tordrillo Mountain Lodge, said the five passengers included three guests and two guides from the lodge.

According to her, Harms was a pioneering heli-ski guide in Alaska who founded a heli-ski company and worked for many years at the lodge.

“Greg was one of the most experienced guides in the business,” said Pruitt.

“This news is devastating to our staff, the community in which we operate and the families of the deceased.”

Tordrillo Mountain Lodge

The richest man in the Czech Republic was also killed in the crash. Kellner, 56, was a “frequent” guest at the lodge, according to Pruitt. Forbes 2020 list of the world’s richest people puts his net worth at over $17 billion.

The National Transportation Safety Board is investigating the cause of the Airbus AS350 B3 crash. All five bodies have been recovered and recovery of the wreckage is now the main focus for investigators.

Timing for the recovery remains uncertain however, as the crash site is only accessibly by helicopter because of the rough terrain and snowy conditions.

A member of the NTSB says the investigation will focus on things like airworthiness, meteorology and human performance in order to not only understand what happened, but how to prevent it from happening again in the future.

The NTSB does not yet have exact information about the weather at the time of the accident, but says that preliminary reports have indicated it was relatively clear.