A plane crash last weekend that crashed with five people on board and no survivors appears to be the deadliest civilian crash ever to occur in Denali National Park, according to National Transportation Safety Board officials.

NTSB investigator Noreen Price said recovery efforts were planned later this week for the plane in Saturday’s crash, which left four of the plane’s occupants dead and the fifth presumed dead. Word of the search’s grim outcome arrived Monday when a Park Ranger suspended from a helicopter and flown to the crash site found four occupants’ bodies.

“We believe it to be the largest fatality at Denali [National] Park, according to our NTSB records,” Price said.

Clint Johnson, the NTSB’s Alaska chief, said Tuesday morning that investigators would arrive in Talkeetna on Wednesday.

It wasn’t clear whether investigators would actually be able to retrieve the de Havilland DHC-2 Beaver, which crashed Saturday night at an altitude of almost 11,000 feet near the summit of the Thunder Mountain ridgeline, about 14 miles southwest of the Denali summit.

A K2 Aviation de Havilland DHC-2 Beaver's Saturday, Aug. 4, 2018 crash site on the Thunder Mountain ridgeline of Denali National Park; four people died in the crash and a fifth is presumed dead. (Credit: Courtesy NPS)

"This is all work in progress and a very, very unique situation,” Johnson said.

According to National Park Service spokeswoman Katherine Belcher, the crash site includes "extremely technical terrain on a hanging glacier that spans a crevasse."

The K2 Aviation flight’s passengers were reported to be Polish tourists, according to search officials. Belcher said no names of the deceased passengers were being released Tuesday, at the request of the Polish Consulate in Los Angeles.

So far only the pilot, Craig Layson of Saline, Mich., has been identified. Searchers said Layson initially reported injuries in the crash by radio, but contact with him was lost as poor weather delayed U.S. Army, Alaska National Guard and National Park Service rescuers’ efforts to reach the aircraft.

A temporary flight restriction in the vicinity of the crash site was lifted by Tuesday.

Scott Gross and Liz Raines contributed information to this story.

Copyright 2018 KTVA. All rights reserved.

RELATED STORIES: