The team said Ronnie Berlack, 20, and Bryce Astle, 19, died in the incident near the Rettenbach glacier in the mountains over Soelden, the venue for the annual season-opening World Cup races.
Berlack, from Franconia, New Hampshire, and Astle, from Sandy, Utah, were part of a group of six skiers who were descending from the 3,056-meter Gaislachkogel when they left the prepared slope and apparently set off the avalanche. The other four skied out of the slide and escaped unhurt.
Officials in the Tyrolean region said an avalanche alert had been declared for the area after days of heavy snowfall and mild temperatures.
"Ronnie and Bryce were both outstanding ski racers who were passionate about their sport -- both on the race course and skiing the mountain," U.S. Ski and Snowboard Association president and CEO Tiger Shaw said. "Our hearts go out to the Berlack and Astle families, as well as to their extended sport family. Both of them loved what they did and conveyed that to those around them."
The tragedy has left the U.S. Ski Team "in shock," Alpine director Patrick Riml told The Associated Press in Zagreb, Croatia, where the American slalom team was preparing for a World Cup race on Tuesday.
Head coach Sascha Rearick left Zagreb shortly after being informed and traveled back to Austria to be with the so-called development team Berlack and Astle were part of.
Riml said the athletes were free to decide whether they still wanted to compete in Tuesday's night race, adding the team planned to wear mourning bands.
"We are all very close," said Riml, an Austrian who was born and grew up in Soelden. "We train a lot in Park City. We'll see how they handle the whole thing and how they react."
Riml added, "it's a shock for everybody. Two great boys, great athletes, good skiers. They were fun to have around. We are all in shock, still. It's very tragic."
Berlack and Astle were part of a group of 10 skiers on the development team who gained experience in the Europa Cup and were preparing to race on the top-level World Cup.
"They all have the potential (to be on the World Cup)," Riml said. "These two boys were among the other eight boys who are our future. We believed in these guys, that's why we selected them."
Berlack was a member of the Franconia Ski Club who recently trained at Vermont's Burke Mountain Academy. He had earned a spot on the development team in 2013 and finished 11th in downhill and 17th in super-G at the National championships that year in Squaw Valley.
Berlack grew up in Franconia, the small town in the White Mountains that also produced U.S., world and Olympic champion Bode Miller. Rich Smith, program director at the Franconia Ski Club, said he had known Berlack since he was 7.
"There's not enough words to say what a great guy Ronnie Berlack was and always will be," Smith said.
In a statement, Burke Mountain Academy said it was devastated by Berlack's death. His father, Steve Berlack, is a coach at the academy. His mother, Cindy, is also a ski coach.
"Only last week Ronnie was here at BMA training with us," the school said. "Ronnie was someone we all loved and deeply respected. He had a huge spirit. There is no one who better represents our core values than Ronnie. Our hearts go out to his parents Steve and Cindy, and his sister Carolyn."
At the Dec. 5 World Cup downhill in Beaver Creek, Berlack was one of the five forerunners, who test a course before the actual race starts. Berlack was also set to be a forerunner during the world championships on the same course next month, U.S ski team spokeswoman Megan Harrod told the AP.
Astle was invited to train with the development team this season after strong early season results, including two top-10 results at NorAm Cup races last month in Canada.
"He was hoping ... to be in the next Olympics, that was his goal," his mother Laura Astle said, "and he was pretty much on his way."
Soelden has been the European base for the U.S. Ski Team since 2011.
Two U.S. Ski Team Prospects Die In Avalanche
Eric Willemsen of the Associated Press talks to Prim Siripipat about the death of two U.S. ski team prospects who died in an avalanche near their European training base.