Shishkova and Naumov, who were married to each other, won the world championships in pairs figure skating in 1994, and they had lived in the United States since 1998, where they trained young ice skaters.

There were 60 passengers and four crew members on the American Airlines flight and three soldiers aboard a training flight on the Black Hawk helicopter. There was no immediate confirmed cause of the collision, but officials said flight conditions were clear as the jet coming from Wichita, Kansas, was making a routine landing when the helicopter flew into its path.

U.S. Figure Skating confirmed that Shishkova and Naumov were on the flight, along with several skaters, coaches and family members, after attending a development camp that followed the national championships that wrapped up on Sunday in Wichita.

“We are heartbroken to learn that figure skaters, along with their families, friends and coaches, are understood to be among those on board,” U.S. Figure Skating said in a statement. “Our thoughts are with everyone affected by this tragedy.

“Figure skating is more than a sport — it’s a close-knit family — and we stand together.”

Shishkova and Naumov became well-known skaters after winning the pairs world title in 1994 in Chiba, Japan. The two-time Olympians later moved to the U.S., first as coaches at the International Skating Centre in Connecticut and later at the Skating Club of Boston in 2017.

One of Shishkova and Naumov’s students is their 23-year-old son, Maxim, who is a former U.S. junior champion and competed in the national championships in Kansas over the weekend.

Ludmila Velikova, who trained Shishkova and Naumov when they were children and who was pivotal to their success, told Reuters that a group of 14 skaters and trainers had been on board the plane.

Velikova said she was devastated by the news of the plane crash, but relieved that the couple’s son had not been on the same plane.

“They were my favourite sports people. They were part of my first attempt at the world championships and became champions in 1994. They were talented and beautiful people,” Velikova told the outlet.

“Apart from anything else they were my children. Zhenya [Shishkova] trained with me from the age of 11 and Vladik [Naumov] from age 14. They were like my own children. What’s happened is awful. The best people have been taken away from us.”

American figure skater Luke Wang also took to social media.

“Praying for all those on the flight from Wichita to DC. Among the passengers were skaters and coaches,” he wrote. “It’s absolutely heartbreaking.”

Officials have not said how many people died in Wednesday night’s midair crash between the airliner and helicopter but suggested that there might be no survivors.

In 1961, the 18-member U.S. figure skating team died in a plane crash en route to the world championships in Prague.