JUNEAU, Alaska (AP) — Foggy, low-visibility conditions hampered efforts to recover the wreckage of a sightseeing plane that crashed in southeast Alaska, killing six people, though federal investigators remained hopeful they could reach the site Sunday, a National Transportation Safety Board official said.

The wreckage was in a rugged, steep area that is heavily forested, at 1,800 feet (548.6 meters) to 2,000 feet (609.6 meters) “up on the side of a mountain,” said Clint Johnson, chief of the agency’s Alaska region. The site is about 12 miles northeast of Ketchikan, Johnson said.

“Very challenging conditions,” Johnson said, adding that the wreckage would have to be removed by helicopter.

He said as of early Sunday afternoon that the team remained on a weather hold. He described conditions at the accident site as having low ceilings, reduced visibility and fog.

Investigators also were conducting interviews in Ketchikan, he said.

The flight was returning to Ketchikan on Thursday from a tour of Misty Fjords National Monument when it crashed, Johnson said.

The plane carried five passengers and the pilot. The Alaska State Troopers identified the pilot as Rolf Lanzendorfer, 64, of Cle Elum, Washington. Troopers identified the passengers as Mark Henderson, 69, and Jacquelyn Komplin, 60, both of Napa, California; Andrea McArthur, 55, and Rachel McArthur, 20, both of Woodstock, Georgia; and Janet Kroll, 77, of Mount Prospect, Illinois.

Troopers and Ketchikan Volunteer Rescue Squad members reached the scene via a chartered helicopter Saturday afternoon and recovered the bodies, which were being taken to the state medical examiner’s office in Anchorage, the troopers said.

Kathleen Grayson, Henderson’s sister, told the Napa Valley Register that Henderson and Komplin had sent messages during their trip “talking about how gorgeous” it was in Alaska. “They were having so much fun,” she said.

Henderson was retired but had worked as a public defender, while Komplin was a registered nurse and instructor at Pacific Union College, the news outlet reported.

Komplin coordinated a wellness program associated with Meals on Wheels for Community Action of Napa Valley, the group’s executive director, Drene Johnson, told The Associated Press. She said Komplin was excited about the trip.

“We were all wishing her well, and that’s what’s so hard for us to comprehend is, now she’s gone,” she said, describing Komplin as “one of a kind.”

One recent post on Kroll’s Facebook page showed Mendenhall Glacier in Juneau in the background. Another was captioned: “I finally made it to Alaska! Hooray!”

Lanzendorfer’s Linkedin profile said he had worked for Southeast Aviation as a pilot since May 2015. Bri Kelly, a media contact for Southeast Aviation, did not provide any details about the pilot’s tenure with the company and directed questions related to the accident to Johnson.

Johnson said Lanzendorfer was the pilot in a July 9 incident in which a Southeast Aviation plane hit an inlet buoy on departure near Coffman Cove and flipped. Alaska State Troopers previously reported the pilot was the only person on board and that no injuries were reported.

Johnson said that’s just “a piece of information that we’re putting on the pile” as investigators probe Thursday’s crash.

Holland America Line confirmed the five passengers on the flight had been traveling on the company’s ship Nieuw Amsterdam, which was nearing the end of seven-day Alaska cruise.

Ketchikan is a popular stop for cruise ships visiting Alaska, and sightseeing excursions, such as those to Misty Fjords National Monument, are among the options for exploring the area while off the ship.

The cruise line said the excursion the passengers were on was not sold by Holland America Line.

Southeast Aviation, in a statement Thursday, said it was cooperating with the agencies involved. “All of us share in the anguish of this tragic incident, and our prayers go out to all affected,” the statement said.

The plane’s emergency beacon was activated about 11:20 a.m. Thursday, the U.S. Coast Guard has said.

A helicopter company reported seeing wreckage on a ridgeline in the search area, and Coast Guard crew members found the wreckage around 2:40 p.m. They reported no survivors, the Coast Guard said.

Weather conditions at the site included mist and light rain, the Coast Guard said.