JUNEAU — A team of aviation investigators is now working in a remote, mountainous site in southeast Alaska to determine what caused the crash of a sightseeing plane that killed eight cruise ship passengers and the aircraft’s pilot.

The DeHavilland DHC-3 Otter turboprop — also known as a floatplane — went down Thursday. The excursion was sold through the cruise company Holland America.

Seven investigators with the National Transportation Safety Board made it to the crash site on Saturday morning and are spending the day scouring for clues to the disaster, said Clint Johnson, head of the board’s Alaska office.

The plane was on its way back from the Misty Fjords National Monument, a wilderness area of lakes, snowcapped peaks and glacial valleys, Johnson said. The terrain where the plane crashed is steep, mountainous, and often sees strong winds and rain.

Johnson said the airplane’s wings and tail broke off during impact, but the fuselage — the body of the plane — was largely intact. Officials said the plane crashed about 25 miles from Ketchikan on a cliff, 800 feet above Ella Lake in steep, muddy terrain. The cause of the crash isn’t yet known.

“It’s way too early to speculate,” Johnson said. “We can’t speculate out of respect to the families.”

Investigators will be looking into weather conditions, pilot qualifications and training records, plane maintenance and inspection records, as well as communications between pilots in the area of the crash, Johnson said. The aircraft was flying in “uncontrolled air space,” but one that’s well-travelled; here pilots of different airplanes talk to each to help each other navigate.

The victims’ remains were flown off the mountain on Friday. The eight victims were passengers on the Holland America Line ship Westerdam. Their 7-day cruise had departed from Seattle on June 20.

Among the deceased was a couple who had found love again later in life.

Rowland Cheney, a 71-year-old artist from Lodi, Calif., planned to propose to Mary Doucette on this trip, said Cheney’s daughter Marin Whitaker on Saturday.

Her dad raised Kiger mustang horses. As an artist, he was known for huge bronze sculptures displayed in the city of Lodi and a senior center in Dublin, California.

Doucette, 59, was a lifelong resident of Lodi. Both had lost longtime spouses in recent years and had found love again.

“Oh we loved Mary, she was such a beautiful person, just lovely,” Whitaker said through tears.

“My dad lived life to the fullest,” she said. “He did everything big, so he did this big too.”

Another passenger who perished in the crash, 31-year-old Glenda Cambiaso, was a social worker in Montgomery County, Maryland in child welfare services. She had previously attended the University of Maryland in Baltimore.

“Her supervisor said she was well liked and loved by her co-workers and that staff were pretty devastated” when they heard the news of her death, said Mary Anderson, a spokeswoman for the Montgomery County Department of Health and Human Services.

Glenda Cambiaso’s father, 65-yer-old Hugo Cambiaso, also died in the crash.

Other victims identified by Alaska State Troopers include June Kranenburg, 73, and Leonard Kranenburg, 63, of Medford, Oregon and Margie Apodaca, 63, and Raymond Apodaca, 70, of Sparks, Nevada.

Ketchikan-based airline Promech Air, operators of the airplane, said the pilot who also died — 64-year-old Bryan Krill, 64, of Hope, Idaho — had joined the company early this year as a summertime pilot.

A company spokeswoman said Krill was a skilled and experienced pilot with a good safety record. He had flown for many years and had 4,300 hours of flight experience, including roughly 1,700 hours piloting single engine seaplanes. The airplane that crashed is one of five floatplanes operated by the company.

“Flying in Alaska was a passion of Bryan’s — he loved his job and loved what he did,” said Marcus Sessoms, president of Promech Air, in a statement. “His loss will be profoundly felt in the aviation community and by anyone who knew him.”

An autopsy will be performed on Krill’s body, said Johnson of the National Transportation Safety Board, standard procedure when any flight crew is killed in an accident.

Johnson said investigators will likely fly the pieces of the airplane via helicopter line to Ketchikan, where it will be reassembled and checked for any mechanical problems.

Sally Andrews, a Holland America Line spokeswoman, said by email that the cruise company is “incredibly saddened by this news and our thoughts and prayers are with the families and friends of those lost in this tragic accident.”

There were 2,095 passengers on the Westerdam. That includes the eight people who died in the crash. The cruise ended in Seattle on Saturday, as scheduled.

Wozniacka reported from Portland, Oregon. Associated Press writers Brett Zongker in Alexandria, Virginia, and Janie Har in San Francisco also contributed to this report.