Four people, including an American skateboarder and a prominent Icelandic aviator, died in a small plane crash last week in Iceland, authorities said on Tuesday.

A massive search and rescue operation on Sunday found the remains of four people in Lake Thingvallavatn, the country’s second-largest lake, about 30 miles east of the capital Reykjavik, said Oddur Arnason, the chief of the South Iceland Police, in an email.

Those believed to be on board the plane before it disappeared from radar on Thursday were Josh Neuman, Haraldur Diego, Nicola Bellavia and Tim Alings, according to family and friends.

The plane, a Cessna 172, was found in the lake at a depth of about 150 feet on Saturday by investigators using sonar and submarine technology, Arnason said. The following day, the remains were found approximately 1,000 feet from the single-engine aircraft.

Mr Arnason said more than 1,000 people took part in the search and rescue efforts, but authorities suspended the recovery operation due to harsh weather conditions. Officials have not said what caused the plane crash.

The death of Mr Bellavia, 32, from Belgium, was confirmed on his Instagram account, where he described himself as “full time on the road exploring”.

Mr Alings, 26, was originally from the Netherlands and worked as a sponsorship manager for a clothing brand, Suspicious Antwerp. A company spokesman, Bram Boriau, confirmed that Mr Alings had died in the accident. “We are extremely saddened by his loss,” Mr. Boriau wrote in an email.

He said Mr. Bellavia and Mr. Neuman, 22, were “friends of the mark” and that someone had recommended the sightseeing flight to the company.

Mr. Neuman’s family confirmed his death in a statement on their Instagram account.

“As the world sheds a tear, we should know he managed to do what he loved, having just experienced the Northern Lights in Iceland for the first time and commenting ‘this is the best day of my life’ ‘” his family said.

Nearly 1.2 million people have subscribed to Mr Neuman’s YouTube page, which has filmed him skateboarding on scenic roads in the United States and Europe. In a series of videos recorded in different parts of the Alps, Mr Neuman raced down the mountains at full speed, with only small guardrails between him and a steep drop down the slopes.

Mr Diego, 50, was a famous photographer and pilot who ran Volcano Air Iceland, an aerial photography travel agency. He has shared photos of his flights over Iceland’s remarkable landscapes on Instagram and YouTube, capturing mountains covered in streams of snow, bubbling lava gushing from volcanoes and rivers meandering through the rugged coastline.

After more than 26 years of flying, Mr. Diego still expressed his admiration for Iceland’s otherworldly terrain. In August, he described watching a six-month-old volcanic eruption near Mount Fagradalsfjall as “one of the most interesting things I’ve ever done”.

“Maybe when I’m old I’ll look at a mountain there and tell my grandkids how it all started,” he wrote on Instagram.

Mr. Diego has also served as President of the Icelandic Association of Aircraft Owners and Pilots. Mark Baker, president of the association’s international body, said in a statement that he had known Mr. Diego and described him as an “energetic person who was 100% invested in everything that it was”.

Chris Burkard, a photographer who flew with Mr Diego to take pictures for his book “At Glacier’s End”, wrote on Instagram that the pilot was a friend who gave him a bed to sleep in when he needed it. “I would attribute much of my success as a person, a photographer and a father to his example,” Burkard said.